content: <PAGE>   1
        
        
               As filed with the Securities and Exchange Commission
                               on October 31, 1996
        
                                                Registration No. 333-
        ==========================================================================
                                                                          
                        SECURITIES AND EXCHANGE COMMISSION
                              Washington, D.C. 20549
        
                                     FORM S-8
        
                           REGISTRATION STATEMENT UNDER
                            THE SECURITIES ACT OF 1933
        
                            BIOTRANSPLANT INCORPORATED
              (Exact name of registrant as specified in its charter)
        
               DELAWARE                                  04-3119555
        (State or other jurisdiction of             (I.R.S. Employer
        incorporation or organization)              Identification Number)
        
             CHARLESTOWN NAVY YARD           
             BUILDING 75, THIRD AVENUE
             CHARLESTOWN, MASSACHUSETTS                02129
         (Address of Principal Executive Offices)    (Zip Code)
         
                           1994 DIRECTORS' EQUITY PLAN
                             (Full title of the Plan)
        
                              ELLIOT LEBOWITZ, PH.D.
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                            BIOTRANSPLANT INCORPORATED
                              CHARLESTOWN NAVY YARD
                            BUILDING 75, THIRD AVENUE
                         CHARLESTOWN, MASSACHUSETTS 02129
                       (Name and address of agent for service)
                                  (617) 241-5200
          (Telephone number, including area code, of agent for service)
                                                                          
        ==========================================================================
  <TABLE>
                        CALCULATION OF REGISTRATION FEE                   
  <CAPTION>
        
                                       Proposed    Proposed
        Title of                       maximum     maximum
        securities        Amount       offering    aggregate        Amount of
        to be             to be        price       offering         registration
        registered        registered   per share   price            fee           
        ----------        ----------   ---------   ---------        -------------
  
        <S>               <C>          <C>         <C>              <C>
        Common            15,000       $6.125(1)   $91,875.00(1)    $100.00
        Stock,            shares    
        $0.01 par
        value per share
        --------------------------------------------------------------------------
  <FN>
  
       (1)  Estimated solely for the purpose of calculating the registration fee
            and based upon the average of the high and low trading prices of the
            Registrant's Common Stock, as reported on the Nasdaq National Market
            on October 29, 1996, in accordance with Rules 457(a) and 457(h) of the
            Securities Act of 1933.
  </TABLE>
                                                                   
  <PAGE>   2
  
  
           PART I.  INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
  
                     The information required by Part I of Form S-8 is included in
           documents sent or given to participants in the 1994 Directors' Equity
           Plan of BioTransplant Incorporated, a Delaware corporation (the
           "Registrant"), pursuant to Rule 428(b)(1) of the Securities Act of
           1933, as amended (the "Securities Act").
  
  
           PART II.  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
                Item 3.  Incorporation of Certain Documents by Reference
                         -----------------------------------------------
  
                     The following documents, which are filed with the Securities
           and Exchange Commission (the "Commission"), are incorporated in this
           Registration Statement by reference:
  
                     (1) The Registrant's latest prospectus filed pursuant to Rule
                424(b) under the Securities Act that contains audited financial
                statements for the Registrant's latest fiscal year for which such
                statements have been filed.
  
                     (2) All other reports filed pursuant to Sections 13(a) or
                15(d) of the Exchange Act since the end of the fiscal year covered
                by the prospectus referred to in (1) above.
  
                     (3) The description of the Common Stock of the Registrant,
                $0.01 par value per share (the "Common Stock"), contained in the
                Registrant's Registration Statement on Form 8-A filed under the
                Exchange Act, including any amendment or report filed for the
                purpose of updating such information.
  
                     All documents subsequently filed by the Registrant pursuant
           to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
           of 1934, as amended (the "Exchange Act"), prior to the filing of a
           post-effective amendment which indicates that all shares of Common
           Stock offered hereby have been sold or which deregisters all shares of
           Common Stock then remaining unsold, shall be deemed to be incorporated
           by reference herein and to be part hereof from the date of the filing
           of such documents.
  
  
                Item 4.  Description of Securities
                         -------------------------
  
                     Not applicable.
  
  
                Item 5.  Interests of Named Experts and Counsel
                         --------------------------------------
  
                     Not applicable.
  
  
  
                                        II-1
  <PAGE>   3
  
  
  
                Item 6.  Indemnification of Directors and Officers
                         -----------------------------------------
  
                     Section 145 of the General Corporation Law of Delaware
           provides that a corporation has the power to indemnify a director,
           officer, employee or agent of the corporation and certain other persons
           serving at the request of the corporation in related capacities against
           amounts paid and expenses incurred in connection with an action or
           proceeding to which such person is or is threatened to be made a party
           by reason of such position, if such person shall have acted in good
           faith and in a manner reasonably believed to be in or not opposed to
           the best interests of the corporation, and, in any criminal proceeding,
           if such person had no reasonable cause to believe such conduct was
           unlawful; provided that, in the case of actions brought by or in the
           right of the corporation, no indemnification shall be made with respect
           to any matter as to which such person shall have been adjudged to be
           liable to the corporation unless and only to the extent that the
           adjudicating court determines that such indemnification is proper under
           the circumstances.
  
                     Article X of the Registrant's Certificate of Incorporation
           provides that a director or officer of the Registrant (a) shall be
           indemnified by the Registrant against all expenses (including
           attorney's fees), judgments, fines and amounts paid in settlement
           reasonably incurred in connection with any litigation or other legal
           proceeding (other than an action by or in the right of the Registrant)
           brought against such director or officer by virtue of a position as a
           director or officer of the Registrant if such director or officer acted
           in good faith and in a manner reasonably believed by such director to
           be in or not opposed to the best interests of the Registrant, and, with
           respect to any criminal action or proceeding, such director had no
           reasonable cause to believe such conduct was unlawful and (b) shall be
           indemnified by the Registrant against expenses (including attorneys'
           fees) and amounts paid in settlement reasonably incurred in connection
           with any action by or in the right of the Registrant by virtue of a
           position as a director or officer of the Registrant if such officer or
           director acted in good faith and in a manner reasonably believed to be
           in or not opposed to the best interests of the Registrant, except that
           no indemnification shall be made with respect to any such matter as to
           which such director or officer shall have been adjudged to be liable to
           the Registrant, unless and only to the extent that a court determines
           that, despite the adjudication of liability but in view of all the
           circumstances of the case, such person is fairly and reasonably
           entitled to indemnity for such expenses as the court deems proper.
           Nothwithstanding the foregoing, to the extent that a director or
           officer has been successful, on the merits or otherwise, such person
           shall be indemnified against all expenses (including attorney's fees)
           reasonably incurred in connection therewith.
  
  
  
                                        II-2
  <PAGE>   4
  
  
           Expenses incurred in defending a civil or criminal action, suit or
           proceeding shall be advanced by the Registrant to a director or
           officer, at such person's request, upon receipt of an undertaking by
           the director or officer to repay such amount if it is ultimately
           determined that such person is not entitled to indemnification.
  
                     Indemnification is required to be made unless the Registrant
           determines that the applicable standard of conduct required for
           information has not been met. In the event of a determination by the
           Registrant that the director or officer did not meet applicable
           standard of conduct required for indemnification, or if the Registrant
           fails to make an indemnification payment within 60 days after such
           payment is claimed by such person, such person is permitted to petition
           a court to make an independent determination as to whether such person
           is entitled to indemnification. As a condition precedent to the right
           of indemnification, the director or officer must give the Registrant
           notice of the action for which indemnity is sought and the Registrant
           has the right to participate in such action or assume the defense
           thereof.
  
                     Article X of the Registrant's Certificate of Incorporation
           further provides that the indemnification provided therein is not
           exclusive, and provides that in the event that the Delaware General
           Corporation Law is amended to expand the indemnification permitted to
           directors or officers, the Registrant must indemnify those persons to
           the fullest extent permitted by such law as so amended.
  
                     Article IX of the Registrant's Certificate of Incorporation
           provides that, except to the extent that the General Corporation Law of
           Delaware prohibits the elimination or limitation of liability of
           directors for breaches of fiduciary duty, no director of the Registrant
           shall be personally liable to the Registrant or its stockholders for
           monetary damages for any breach of fiduciary duty as a director.
  
                     The Registrant has purchased a general liability insurance
           policy which covers certain liabilities of directors and officers of
           the Registrant arising out of claims based on acts or omissions in
           their capacity as directors or officers.
  
                Item 7.  Exemption from Registration Claimed
                         -----------------------------------
  
                     Not applicable.
  
  
                Item 8.  Exhibits
                         --------
  
                     The Exhibit Index immediately preceding the exhibits is
           incorporated herein by reference.
  
  
  
                                        II-3
  <PAGE>   5
  
  
                Item 9.  Undertakings
                         ------------
  
                1.   The Registrant hereby undertakes:
  
                     (a) To file, during any period in which offers or sales are
                being made, a post-effective amendment to this Registration
                Statement:
  
                     (i) To include any prospectus required by Section 10(a)(3) of
                         the Securities Act;
  
                    (ii) To reflect in the prospectus any facts or events arising
                         after the effective date of the Registration Statement 
                         (or the most recent post-effective amendment thereof) 
                         which, individually or in the aggregate, represent a 
                         fundamental change in the information set forth in the 
                         Registration Statement; and
  
                   (iii) To include any material information with respect to the 
                         plan of distribution not previously disclosed in the 
                         Registration Statement or any material change to such 
                         information in the Registration Statement;
  
                PROVIDED, HOWEVER, that paragraphs (i) and (ii) do not apply if 
                the Registration Statement is on Form S-3 or Form S-8, and the
                information required to be included in a post-effective amendment
                by those paragraphs is contained in periodic reports filed by the
                Registrant pursuant to Section 13 or Section 15(d) of the Exchange
                Act that are incorporated by reference in the Registration
                Statement.
  
                     (b) That, for the purpose of determining any liability under
                the Securities Act, each such post-effective amendment shall be
                deemed to be a new Registration Statement relating to the
                securities offered therein, and the offering of such securities at
                that time shall be deemed to be the initial bona fide offering
                thereof.
  
                     (c) To remove from registration by means of a post-effective
                amendment any of the securities being registered which remain
                unsold at the termination of the offering.
  
                2. The Registrant hereby undertakes that, for purposes of
           determining any liability under the Securities Act, each filing of the
           Registrant's annual report pursuant to Section 13(a) or Section 15(d)
           of the Exchange Act (and, where applicable, each filing of an employee
           benefit plan's annual report pursuant to Section 15(d) of the Exchange
           Act) that is incorporated by
  
  
                                        II-4
  
  
  <PAGE>   6
  
  
  
           reference in the Registration Statement shall be deemed to be a new
           Registration Statement relating to the securities offered therein, and
           the offering of such securities at that time shall be deemed to be the
           initial bona fide offering thereof.
  
                3. Insofar as indemnification for liabilities arising under the
           Securities Act may be permitted to directors, officers and controlling
           persons of the Registrant pursuant to the foregoing provisions, or
           otherwise, the Registrant has been advised that in the opinion of the
           Securities and Exchange Commission such indemnification is against
           public policy as expressed in the Securities Act and is, therefore,
           unenforceable. In the event that a claim for indemnification against
           such liabilities (other than the payment by the Registrant of expenses
           incurred or paid by a director, officer or controlling person of the
           Registrant in the successful defense of any action, suit or proceeding)
           is asserted by such director, officer or controlling person in
           connection with the securities being registered, the Registrant will,
           unless in the opinion of its counsel the matter has been settled by
           controlling precedent, submit to a court of appropriate jurisdiction
           the question whether such indemnification by it is against public
           policy as expressed in the Securities Act and will be governed by the
           final adjudication of such issue.
  
  
  
                                        II-5
  
  
  <PAGE>   7
  
  
  
                                       SIGNATURES
  
                Pursuant to the requirements of the Securities Act, the Registrant
           certifies that it has reasonable grounds to believe that it meets all
           of the requirements for filing on Form S-8 and has duly caused this
           Registration Statement to be signed on its behalf by the undersigned,
           thereunto duly authorized, in the Town of Charlestown, Commonwealth of
           Massachusetts, this 30th day of October, 1996.
  
  
                                              BioTransplant Incorporated
  
  
  
  
                                              By:  /s/ Elliot Lebowitz
                                                 ------------------------
                                                 Elliot Lebowitz
                                                 President and
                                                 Chief Executive Officer
  
  
  
  
                                   POWER OF ATTORNEY
  
                We, the undersigned officers and directors of BioTransplant
           Incorporated, hereby severally constitute and appoint Elliot Lebowitz,
           Richard V. Capasso and Steven D. Singer, and each of them singly, our
           true and lawful attorneys with full power to them, and each of them
           singly, to sign for us and in our names, in the capacities indicated
           below, the Registration Statement on Form S-8 filed herewith, and any
           and all subsequent amendments to said Registration Statement, and
           generally to do all such things in our names and on our behalf and in
           our capacities as officers and directors to enable BioTransplant
           Incorporated to comply with the provisions of the Securities Act of
           1933, as amended, and all requirements of the Securities and Exchange
           Commission, hereby ratifying and confirming our signatures as they may
           be signed by our said attorneys, or any of them, to said Registration
           Statement and any and all amendments thereto.
  
  
  
                                        II-6
  
  
  <PAGE>   8
  
  <TABLE>
                Pursuant to the requirements of the Securities Act, this
           Registration Statement has been signed below by the following persons
           in the capacities and on the dates indicated.
  <CAPTION>
  
                   Signature                    Title               Date
                   ---------                    -----               ----
  
           <S>                           <C>                   <C>
           /s/ Elliot Lebowitz           President, Chief      October 30, 1996
           -----------------------         Executive Officer
           Elliot Lebowitz                 and Director     
                                           (Principal       
                                            Executive       
                                            Officer)        
                                           
           /s/ Richard V. Capasso        Director of           October 30, 1996
           -----------------------         Finance (Principal  
           Richard V. Capasso              Financial and       
                                           Accounting Officer) 
                                           
  
           /s/ William W. Crouse         Director              October 30, 1996
           -----------------------
           William W. Crouse
  
           /s/ James C. Foster           Director              October 30, 1996
           -----------------------
           James C. Foster
  
           /s/ Daniel O. Hauser          Director              October 30, 1996
           -----------------------
           Daniel O. Hauser
  
           -----------------------       Director              October __, 1996
           Robert A. Vukovich
  
           /s/ Daniel P. Kearney         Director              October 30, 1996
           -----------------------
           Daniel P. Kearney
  
  </TABLE>
  
  
                                        II-7
  
  <PAGE>   9
  
  <TABLE>
  
                                     Exhibit Index
  <CAPTION>
  
  
      Exhibit
      Number       Description                                         Page
      -------      -----------                                         ----
  
        <S>        <C>                                                 <C> 
         4.1 (1)   Restated Certificate of Incorporation,
                   as amended to date.                                 --
  
         4.2 (1)   By-laws, as amended to date                         --
  
         4.3 (1)   Specimen Certificate of Common Stock,               --
                   $0.01 par value, of the Registrant
  
         5         Opinion of Hale and Dorr
  
        23.1       Consent of Hale and Dorr                            --
                   (included in Exhibit 5)
  
        23.2       Consent of Arthur Andersen LLP
  
        24         Power of Attorney (included on the signature        --
                   page of this Registration Statement)
  
  
  <FN>
  
  ------------------
  
      (1)  Incorporated herein by reference to the Registrant's Registration
           Statement on Form S-1 (File No. 333-2144).
  </TABLE>
metadata_documents: [{"type": "S-8", "sequence": "1", "description": "BIOTRANSPLANT INCORPORATED 1994 DIRECTORS EQUITY", "secsgml_size_bytes": 21890}]
metadata_filer: {"company-data": {"conformed-name": "BIOTRANSPLANT INC", "cik": "0000880259", "assigned-sic": "2834", "irs-number": "043119555", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-15249", "film-number": "96651447"}, "business-address": {"street1": "BUILDING 75, 3RD AVENUE", "street2": "BLDG 96 13TH ST", "city": "CHARLESTOWN", "state": "MA", "zip": "02129", "phone": "6172415200"}}
text: 1
        
        
               As filed with the Securities and Exchange Commission
                               on October 31, 1996
        
                                                Registration No. 333-
        ==========================================================================
                                                                          
                        SECURITIES AND EXCHANGE COMMISSION
                              Washington, D.C. 20549
        
                                     FORM S-8
        
                           REGISTRATION STATEMENT UNDER
                            THE SECURITIES ACT OF 1933
        
                            BIOTRANSPLANT INCORPORATED
              (Exact name of registrant as specified in its charter)
        
               DELAWARE                                  04-3119555
        (State or other jurisdiction of             (I.R.S. Employer
        incorporation or organization)              Identification Number)
        
             CHARLESTOWN NAVY YARD           
             BUILDING 75, THIRD AVENUE
             CHARLESTOWN, MASSACHUSETTS                02129
         (Address of Principal Executive Offices)    (Zip Code)
         
                           1994 DIRECTORS' EQUITY PLAN
                             (Full title of the Plan)
        
                              ELLIOT LEBOWITZ, PH.D.
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                            BIOTRANSPLANT INCORPORATED
                              CHARLESTOWN NAVY YARD
                            BUILDING 75, THIRD AVENUE
                         CHARLESTOWN, MASSACHUSETTS 02129
                       (Name and address of agent for service)
                                  (617) 241-5200
          (Telephone number, including area code, of agent for service)
                                                                          
        ==========================================================================
  
                        CALCULATION OF REGISTRATION FEE
  Proposed    Proposed
        Title of                       maximum     maximum
        securities        Amount       offering    aggregate        Amount of
        to be             to be        price       offering         registration
        registered        registered   per share   price            fee           
        ----------        ----------   ---------   ---------        -------------
  Common            15,000       $6.125(1)   $91,875.00(1)    $100.00
        Stock,            shares    
        $0.01 par
        value per share
        --------------------------------------------------------------------------
  (1)  Estimated solely for the purpose of calculating the registration fee
            and based upon the average of the high and low trading prices of the
            Registrant's Common Stock, as reported on the Nasdaq National Market
            on October 29, 1996, in accordance with Rules 457(a) and 457(h) of the
            Securities Act of 1933.
  2
  
           PART I.  INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
  
                     The information required by Part I of Form S-8 is included in
           documents sent or given to participants in the 1994 Directors' Equity
           Plan of BioTransplant Incorporated, a Delaware corporation (the
           "Registrant"), pursuant to Rule 428(b)(1) of the Securities Act of
           1933, as amended (the "Securities Act").
  
           PART II.  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
                Item 3.  Incorporation of Certain Documents by Reference
                         -----------------------------------------------
  
                     The following documents, which are filed with the Securities
           and Exchange Commission (the "Commission"), are incorporated in this
           Registration Statement by reference:
  
                     (1) The Registrant's latest prospectus filed pursuant to Rule
                424(b) under the Securities Act that contains audited financial
                statements for the Registrant's latest fiscal year for which such
                statements have been filed.
  
                     (2) All other reports filed pursuant to Sections 13(a) or
                15(d) of the Exchange Act since the end of the fiscal year covered
                by the prospectus referred to in (1) above.
  
                     (3) The description of the Common Stock of the Registrant,
                $0.01 par value per share (the "Common Stock"), contained in the
                Registrant's Registration Statement on Form 8-A filed under the
                Exchange Act, including any amendment or report filed for the
                purpose of updating such information.
  
                     All documents subsequently filed by the Registrant pursuant
           to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
           of 1934, as amended (the "Exchange Act"), prior to the filing of a
           post-effective amendment which indicates that all shares of Common
           Stock offered hereby have been sold or which deregisters all shares of
           Common Stock then remaining unsold, shall be deemed to be incorporated
           by reference herein and to be part hereof from the date of the filing
           of such documents.
  
                Item 4.  Description of Securities
                         -------------------------
  
                     Not applicable.
  
                Item 5.  Interests of Named Experts and Counsel
                         --------------------------------------
  
                     Not applicable.
  
                                        II-1
  3
  
                Item 6.  Indemnification of Directors and Officers
                         -----------------------------------------
  
                     Section 145 of the General Corporation Law of Delaware
           provides that a corporation has the power to indemnify a director,
           officer, employee or agent of the corporation and certain other persons
           serving at the request of the corporation in related capacities against
           amounts paid and expenses incurred in connection with an action or
           proceeding to which such person is or is threatened to be made a party
           by reason of such position, if such person shall have acted in good
           faith and in a manner reasonably believed to be in or not opposed to
           the best interests of the corporation, and, in any criminal proceeding,
           if such person had no reasonable cause to believe such conduct was
           unlawful; provided that, in the case of actions brought by or in the
           right of the corporation, no indemnification shall be made with respect
           to any matter as to which such person shall have been adjudged to be
           liable to the corporation unless and only to the extent that the
           adjudicating court determines that such indemnification is proper under
           the circumstances.
  
                     Article X of the Registrant's Certificate of Incorporation
           provides that a director or officer of the Registrant (a) shall be
           indemnified by the Registrant against all expenses (including
           attorney's fees), judgments, fines and amounts paid in settlement
           reasonably incurred in connection with any litigation or other legal
           proceeding (other than an action by or in the right of the Registrant)
           brought against such director or officer by virtue of a position as a
           director or officer of the Registrant if such director or officer acted
           in good faith and in a manner reasonably believed by such director to
           be in or not opposed to the best interests of the Registrant, and, with
           respect to any criminal action or proceeding, such director had no
           reasonable cause to believe such conduct was unlawful and (b) shall be
           indemnified by the Registrant against expenses (including attorneys'
           fees) and amounts paid in settlement reasonably incurred in connection
           with any action by or in the right of the Registrant by virtue of a
           position as a director or officer of the Registrant if such officer or
           director acted in good faith and in a manner reasonably believed to be
           in or not opposed to the best interests of the Registrant, except that
           no indemnification shall be made with respect to any such matter as to
           which such director or officer shall have been adjudged to be liable to
           the Registrant, unless and only to the extent that a court determines
           that, despite the adjudication of liability but in view of all the
           circumstances of the case, such person is fairly and reasonably
           entitled to indemnity for such expenses as the court deems proper.
           Nothwithstanding the foregoing, to the extent that a director or
           officer has been successful, on the merits or otherwise, such person
           shall be indemnified against all expenses (including attorney's fees)
           reasonably incurred in connection therewith.
  
                                        II-2
  4
  
           Expenses incurred in defending a civil or criminal action, suit or
           proceeding shall be advanced by the Registrant to a director or
           officer, at such person's request, upon receipt of an undertaking by
           the director or officer to repay such amount if it is ultimately
           determined that such person is not entitled to indemnification.
  
                     Indemnification is required to be made unless the Registrant
           determines that the applicable standard of conduct required for
           information has not been met. In the event of a determination by the
           Registrant that the director or officer did not meet applicable
           standard of conduct required for indemnification, or if the Registrant
           fails to make an indemnification payment within 60 days after such
           payment is claimed by such person, such person is permitted to petition
           a court to make an independent determination as to whether such person
           is entitled to indemnification. As a condition precedent to the right
           of indemnification, the director or officer must give the Registrant
           notice of the action for which indemnity is sought and the Registrant
           has the right to participate in such action or assume the defense
           thereof.
  
                     Article X of the Registrant's Certificate of Incorporation
           further provides that the indemnification provided therein is not
           exclusive, and provides that in the event that the Delaware General
           Corporation Law is amended to expand the indemnification permitted to
           directors or officers, the Registrant must indemnify those persons to
           the fullest extent permitted by such law as so amended.
  
                     Article IX of the Registrant's Certificate of Incorporation
           provides that, except to the extent that the General Corporation Law of
           Delaware prohibits the elimination or limitation of liability of
           directors for breaches of fiduciary duty, no director of the Registrant
           shall be personally liable to the Registrant or its stockholders for
           monetary damages for any breach of fiduciary duty as a director.
  
                     The Registrant has purchased a general liability insurance
           policy which covers certain liabilities of directors and officers of
           the Registrant arising out of claims based on acts or omissions in
           their capacity as directors or officers.
  
                Item 7.  Exemption from Registration Claimed
                         -----------------------------------
  
                     Not applicable.
  
                Item 8.  Exhibits
                         --------
  
                     The Exhibit Index immediately preceding the exhibits is
           incorporated herein by reference.
  
                                        II-3
  5
  
                Item 9.  Undertakings
                         ------------
  
                1.   The Registrant hereby undertakes:
  
                     (a) To file, during any period in which offers or sales are
                being made, a post-effective amendment to this Registration
                Statement:
  
                     (i) To include any prospectus required by Section 10(a)(3) of
                         the Securities Act;
  
                    (ii) To reflect in the prospectus any facts or events arising
                         after the effective date of the Registration Statement 
                         (or the most recent post-effective amendment thereof) 
                         which, individually or in the aggregate, represent a 
                         fundamental change in the information set forth in the 
                         Registration Statement; and
  
                   (iii) To include any material information with respect to the 
                         plan of distribution not previously disclosed in the 
                         Registration Statement or any material change to such 
                         information in the Registration Statement;
  
                PROVIDED, HOWEVER, that paragraphs (i) and (ii) do not apply if 
                the Registration Statement is on Form S-3 or Form S-8, and the
                information required to be included in a post-effective amendment
                by those paragraphs is contained in periodic reports filed by the
                Registrant pursuant to Section 13 or Section 15(d) of the Exchange
                Act that are incorporated by reference in the Registration
                Statement.
  
                     (b) That, for the purpose of determining any liability under
                the Securities Act, each such post-effective amendment shall be
                deemed to be a new Registration Statement relating to the
                securities offered therein, and the offering of such securities at
                that time shall be deemed to be the initial bona fide offering
                thereof.
  
                     (c) To remove from registration by means of a post-effective
                amendment any of the securities being registered which remain
                unsold at the termination of the offering.
  
                2. The Registrant hereby undertakes that, for purposes of
           determining any liability under the Securities Act, each filing of the
           Registrant's annual report pursuant to Section 13(a) or Section 15(d)
           of the Exchange Act (and, where applicable, each filing of an employee
           benefit plan's annual report pursuant to Section 15(d) of the Exchange
           Act) that is incorporated by
  
                                        II-4
  6
  
           reference in the Registration Statement shall be deemed to be a new
           Registration Statement relating to the securities offered therein, and
           the offering of such securities at that time shall be deemed to be the
           initial bona fide offering thereof.
  
                3. Insofar as indemnification for liabilities arising under the
           Securities Act may be permitted to directors, officers and controlling
           persons of the Registrant pursuant to the foregoing provisions, or
           otherwise, the Registrant has been advised that in the opinion of the
           Securities and Exchange Commission such indemnification is against
           public policy as expressed in the Securities Act and is, therefore,
           unenforceable. In the event that a claim for indemnification against
           such liabilities (other than the payment by the Registrant of expenses
           incurred or paid by a director, officer or controlling person of the
           Registrant in the successful defense of any action, suit or proceeding)
           is asserted by such director, officer or controlling person in
           connection with the securities being registered, the Registrant will,
           unless in the opinion of its counsel the matter has been settled by
           controlling precedent, submit to a court of appropriate jurisdiction
           the question whether such indemnification by it is against public
           policy as expressed in the Securities Act and will be governed by the
           final adjudication of such issue.
  
                                        II-5
  7
  
                                       SIGNATURES
  
                Pursuant to the requirements of the Securities Act, the Registrant
           certifies that it has reasonable grounds to believe that it meets all
           of the requirements for filing on Form S-8 and has duly caused this
           Registration Statement to be signed on its behalf by the undersigned,
           thereunto duly authorized, in the Town of Charlestown, Commonwealth of
           Massachusetts, this 30th day of October, 1996.
  
                                              BioTransplant Incorporated
  
                                              By:  /s/ Elliot Lebowitz
                                                 ------------------------
                                                 Elliot Lebowitz
                                                 President and
                                                 Chief Executive Officer
  
                                   POWER OF ATTORNEY
  
                We, the undersigned officers and directors of BioTransplant
           Incorporated, hereby severally constitute and appoint Elliot Lebowitz,
           Richard V. Capasso and Steven D. Singer, and each of them singly, our
           true and lawful attorneys with full power to them, and each of them
           singly, to sign for us and in our names, in the capacities indicated
           below, the Registration Statement on Form S-8 filed herewith, and any
           and all subsequent amendments to said Registration Statement, and
           generally to do all such things in our names and on our behalf and in
           our capacities as officers and directors to enable BioTransplant
           Incorporated to comply with the provisions of the Securities Act of
           1933, as amended, and all requirements of the Securities and Exchange
           Commission, hereby ratifying and confirming our signatures as they may
           be signed by our said attorneys, or any of them, to said Registration
           Statement and any and all amendments thereto.
  
                                        II-6
  8
  
                Pursuant to the requirements of the Securities Act, this
           Registration Statement has been signed below by the following persons
           in the capacities and on the dates indicated.
  Signature                    Title               Date
                   ---------                    -----               ----
  /s/ Elliot Lebowitz           President, Chief      October 30, 1996
           -----------------------         Executive Officer
           Elliot Lebowitz                 and Director     
                                           (Principal       
                                            Executive       
                                            Officer)        
                                           
           /s/ Richard V. Capasso        Director of           October 30, 1996
           -----------------------         Finance (Principal  
           Richard V. Capasso              Financial and       
                                           Accounting Officer) 
                                           
  
           /s/ William W. Crouse         Director              October 30, 1996
           -----------------------
           William W. Crouse
  
           /s/ James C. Foster           Director              October 30, 1996
           -----------------------
           James C. Foster
  
           /s/ Daniel O. Hauser          Director              October 30, 1996
           -----------------------
           Daniel O. Hauser
  
           -----------------------       Director              October __, 1996
           Robert A. Vukovich
  
           /s/ Daniel P. Kearney         Director              October 30, 1996
           -----------------------
           Daniel P. Kearney
  II-7
  9
  
                                     Exhibit Index
  Exhibit
      Number       Description                                         Page
      -------      -----------                                         ----
  4.1 (1)   Restated Certificate of Incorporation,
                   as amended to date.                                 --
  
         4.2 (1)   By-laws, as amended to date                         --
  
         4.3 (1)   Specimen Certificate of Common Stock,               --
                   $0.01 par value, of the Registrant
  
         5         Opinion of Hale and Dorr
  
        23.1       Consent of Hale and Dorr                            --
                   (included in Exhibit 5)
  
        23.2       Consent of Arthur Andersen LLP
  
        24         Power of Attorney (included on the signature        --
                   page of this Registration Statement)
  ------------------
  
      (1)  Incorporated herein by reference to the Registrant's Registration
           Statement on Form S-1 (File No. 333-2144).