content: <PAGE>   1
  
      As filed with the Securities and Exchange Commission on December 4, 2000
  
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                         ----------------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                         ----------------------------------
  
          DELAWARE                                    06-1555163
  (STATE OF INCORPORATION)                 (I.R.S. EMPLOYER IDENTIFICATION NO.)
  
                              MCK COMMUNICATIONS, INC.
                                117 KENDRICK STREET
                            NEEDHAM, MASSACHUSETTS 02494
                                   (617) 454-6100
      (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                    OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
  
                               FULL TITLE OF THE PLAN
  
                         2000 EMPLOYEE STOCK PURCHASE PLAN
  
                         ----------------------------------
  
                                  STEVEN J. BENSON
                   CHAIRMAN, CHIEF EXECUTIVE OFFICER AND DIRECTOR
                              MCK COMMUNICATIONS, INC.
                                117 KENDRICK STREET
                            NEEDHAM, MASSACHUSETTS 02494
                                   (617) 454-6100
  
  (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                               OF AGENT FOR SERVICE)
  
                         ----------------------------------
  
                                  With copies to:
                                    Sally Burke
                              MCK Communications, Inc.
                                117 Kendrick Street
                            Needham, Massachusetts 02494
                                   (617) 454-6100
  
  
                          CALCULATION OF REGISTRATION FEE
  <TABLE>
  <CAPTION>
  
  ====================================================================================================================
  
                                                                               Proposed Maximum
                                   Amounts to be      Proposed Maximum        Aggregate Offering         Amount of
                                    Registered   Offering Price Per Share (1)     Price(1)          Registration Fee
  --------------------------------------------------------------------------------------------------------------------
  <S>                                <C>                <C>                       <C>                   <C>
  Common Stock issuable pursuant
  to the 2000 Employee Stock         500,000              $5.6875                 $2,843,750             $750.75
  Purchase Plan
  ====================================================================================================================
  
  </TABLE>
  
  
  (1)  The Proposed Maximum Offering Price Per Share and the Proposed Aggregate
       Offering Price are based upon the average of the high and low prices for
       the Registrant's Common Stock, par value $.001 per share, as reported on
       the Nasdaq National Market on November 30, 2000, in accordance with Rules
       457(h) and (c) under the Securities Act of 1933, as amended, and are
       utilized solely for the purpose of calculating the registration fee.
  
  <PAGE>   2
                                       PART I
  
                INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS
  
  Item 1.  PLAN INFORMATION. *
  
  Item 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION. *
  
           * Information required by Part I to be contained in the Section 10(a)
  Prospectus is omitted from this Registration Statement in accordance with Rule
  428 under the Securities Act of 1933 (the "Securities Act") and the Introductory
  Note to Part I of Form S-8.
  
                                      PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  Item 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.
  
           MCK Communications, Inc. (the "Registrant") hereby incorporates by
           reference the following documents which have previously been filed with
           the Securities and Exchange Commission:
  
           (a)      the Registrant's Annual Report on Form 10-K for the fiscal
                    year ended April 30, 2000 filed with the Securities and
                    Exchange Commission on July 31, 2000 (File No. 000-32090);
  
           (b)      all other reports filed with the Securities and Exchange
                    Commission by the Registrant pursuant to Section 13(a) or
                    15(d) of the Securities Exchange Act of 1934, as amended (the
                    "Exchange Act") since April 30, 2000; and
  
           (c)      the description of the Registrant's Common Stock contained in
                    the Registration Statement on Form 8-A dated October 18, 1999
                    as filed with the Securities and Exchange Commission on
                    October 18, 1999 pursuant to Section 12(g) of the Securities
                    Exchange Act of 1934, as amended.
  
           In addition, all documents subsequently filed with the Securities and
  Exchange Commission by the Registrant pursuant to Sections 13(a), 13(c), 14 and
  15(d) of the Exchange Act, prior to the filing of a post-effective amendment
  hereto that indicates that all securities offered hereunder have been sold or
  which deregisters all securities then remaining unsold, shall be deemed to be
  incorporated by reference in this Registration Statement and to be a part hereof
  from the date of filing of such documents. Any statement contained in a document
  incorporated by reference herein shall be deemed to be modified or superseded
  for purposes hereof to the extent that a statement contained herein or in any
  subsequently filed document which also is incorporated by reference herein
  modifies or supersedes such statement. Any statement so modified or superseded
  shall not be deemed, except as so modified or superseded, to constitute a part
  of this Registration Statement.
  
  Item 4.  DESCRIPTION OF SECURITIES.
  
           Not Applicable.
  
  Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           Not Applicable.
  
  Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           In accordance with Section 145 of the General Corporation Law of the
  State of Delaware ("DGCL"), Article VII of the Registrant's Amended and Restated
  Certificate of Incorporation (the "Certificate") provides that no director of
  the Registrant shall be personally liable to the Registrant or its stockholders
  for monetary damages for breach of fiduciary duty as a director, except for
  liability (i) for any breach of the director's duty of loyalty to the Registrant
  or its stockholders, (ii) for acts or omissions not in good faith or which
  involve intentional misconduct or a knowing violation of law, (iii) in respect
  of intentional misconduct or a knowing violation of law, (iii) in respect of
  certain unlawful dividend payments or stock redemptions or repurchases, or (iv)
  for any transaction from which the director derived an improper personal
  benefit. In addition, the Certificate provides that if the DGCL is amended to
  authorize the further elimination or limitation of the personal liability of
  directors, then the liability of a director of the Registrant shall be
  eliminated or limited to the fullest extent permitted by the DGCL, as so
  amended.
  
           Article V of the Registrant's Amended and Restated By-laws (the
  "By-laws") provides for indemnification by the Registrant of its directors,
  officers and certain non-officer employees (including officers and certain
  non-officer employees of subsidiaries) under certain circumstances against
  expenses (including attorneys fees, judgments, fines and amounts paid in
  settlement) reasonably incurred in connection with the defense or settlement of
  any threatened, pending or completed legal proceeding in which any such person
  is involved by reason of the fact that such person is or was a director, an
  officer or an employee of the Registrant, or is acting in any capacity with
  other entities at the written request of the registrant, if such person acted in
  good faith and in a manner he or she reasonably believed to be in, or not
  opposed to, the best interests of the Registrant, and with respect to criminal
  actions or proceedings, that such person had no reasonable cause to believe his
  or her conduct was unlawful.
  
           Under Section 7 of the Underwriting Agreement filed as Exhibit 1.1 to
  the MCK Communications, Inc. Registration Statement on Form S-1 (File No.
  333-85821), the Underwriters have agreed to indemnify, under certain conditions,
  the Registrant, its directors, certain officers and persons who control the
  Registrant within the meaning of the Securities Act against certain liabilities.
  
           The Company carries directors' and officers' liability insurance
  covering its directors and officers.
  
  Item 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  Item 8.  EXHIBITS.
  
  
                                         2
  <PAGE>   3
  
           The following is a complete list of exhibits filed or incorporated by
  reference as part of this Registration Statement.
  
  EXHIBITS
  --------
  
           5.1      Opinion of McDermott, Will & Emery as to the legality of the
                    securities being offered
  
           23.1     Consent of McDermott, Will & Emery (included in Exhibit 5.1)
  
           23.2     Consent of Ernst & Young LLP
  
           23.3     Powers of Attorney (included on signature pages to this
                    Registration Statement)
  
           99.1     2000 Employee Stock Purchase Plan of the Registrant
  
  ------------------------
  
  Item 9.  UNDERTAKINGS.
  
           (a)   The undersigned Registrant hereby undertakes:
  
                 (1)  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 acts 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.
                 Notwithstanding the foregoing, any increase or decrease in volume
                 of securities offered (if the total dollar value of securities
                 offered would not exceed that which was registered) and any
                 deviation from the low or high end of the estimated offering
                 range may be reflected in the form of prospectus filed with the
                 Commission pursuant to Rule 424(b) if, in the aggregate, the
                 changes in volume and price represent no more than a twenty
                 percent (20%) change in the maximum aggregate offering price set
                 forth in the "Calculation of Registration Fee" table in the
                 effective 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 (a)(1)(i) and (a)(1)(ii) herein do
           not apply if the Registration Statement is on Form S-3, Form S-8 or
           Form F-3, and the information required to be included in a
           post-effective amendment by those paragraphs is contained in periodic
           reports filed by the undersigned Registrant pursuant to Section 13 or
           Section 15 (d) of the Exchange Act that are incorporated by reference
           in the Registration Statement;
  
                 (2)  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; and
  
                 (3)  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.
  
           (b) The undersigned 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 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
  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.
  
           (c) 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.
  
                                         3
  <PAGE>   4
  
           Pursuant to the requirements of the Securities Act, MCK Communications,
  Inc. 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 Newton, Massachusetts on November 30, 2000.
  
                                           MCK Communications, Inc.
  
                                           By: /s/ Steven J. Benson
                                              ----------------------------------
                                               Steven J. Benson
                                               Chairman, Chief Executive Officer
                                               and President
  
  
                                  POWER OF ATTORNEY
  
           KNOW ALL MEN BY THESE PRESENTS that each individual whose signature
  appears below constitutes and appoints each of Steven J. Benson and Paul K.
  Zurlo such person's true and lawful attorney-in-fact and agent with full power
  of substitution and resubstitution for such period and in such person's name,
  place and stead, in any and all capacities, to sign any and all amendments
  (including post-effective amendments) to this Registration Statement, and to
  file with same, with all exhibits thereto, and all documents in connection
  therewith, with the Securities and Exchange Commission, granting unto each said
  attorney-in-fact and agent full power and authority to do and perform each and
  every act and thing requisite and necessary to be done in and about the
  premises, as fully to all intents and purposes as such person might or could do
  in person, hereby ratifying and confirming all that any said attorney-in-fact
  and agent, or any substitute or substitutes of any of them, may lawfully do or
  cause to be done by virtue hereof.
  
           Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  
  <TABLE>
  <CAPTION>
  
  SIGNATURE                   TITLE                                               DATE
  
  <S>                         <C>                                             <C>
  /s/ Steven J. Benson        Chairman of the Board, (Chief Executive         November 30, 2000
  -------------------------   Officer, President, Chairman and Director)
  Steven J. Benson
  
  /s/ Paul K. Zurlo           Chief Financial Officer (Principal Financial    November 30, 2000
  -------------------------   and Accounting Officer)
  Paul K. Zurlo
  
                              Director
  -------------------------
  Calvin K. Manz
  
  /s/ John B. Landry          Director                                        November 30, 2000
  -------------------------
  John B. Landry
  
  /s/ Gregory M. Avis         Director                                        November 30, 2000
  -------------------------
  Gregory M. Avis
  
  /s/ Michael H. Balmuth      Director                                        November 30, 2000
  -------------------------
  Michael H. Balmuth
  
                              Director
  -------------------------
  Paul Severino
  
  </TABLE>
  
  
                                         4
  <PAGE>   5
  
                                    EXHIBIT INDEX
  
  
  EXHIBITS
  --------
  
    5.1     Opinion of McDermott, Will & Emery as to the legality of the
            securities being offered
  
   23.1     Consent of McDermott, Will & Emery (included in Exhibit 5.1)
  
   23.2     Consent of Ernst & Young LLP
  
   23.3     Powers of Attorney (included on signature pages to this Registration
            Statement)
  
   99.1     2000 Employee Stock Purchase Plan of the Registrant
  
  ----------------
  
  
                                         5
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text: 1
  
      As filed with the Securities and Exchange Commission on December 4, 2000
  
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                         ----------------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                         ----------------------------------
  
          DELAWARE                                    06-1555163
  (STATE OF INCORPORATION)                 (I.R.S. EMPLOYER IDENTIFICATION NO.)
  
                              MCK COMMUNICATIONS, INC.
                                117 KENDRICK STREET
                            NEEDHAM, MASSACHUSETTS 02494
                                   (617) 454-6100
      (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                    OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
  
                               FULL TITLE OF THE PLAN
  
                         2000 EMPLOYEE STOCK PURCHASE PLAN
  
                         ----------------------------------
  
                                  STEVEN J. BENSON
                   CHAIRMAN, CHIEF EXECUTIVE OFFICER AND DIRECTOR
                              MCK COMMUNICATIONS, INC.
                                117 KENDRICK STREET
                            NEEDHAM, MASSACHUSETTS 02494
                                   (617) 454-6100
  
  (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING AREA CODE,
                               OF AGENT FOR SERVICE)
  
                         ----------------------------------
  
                                  With copies to:
                                    Sally Burke
                              MCK Communications, Inc.
                                117 Kendrick Street
                            Needham, Massachusetts 02494
                                   (617) 454-6100
  
                          CALCULATION OF REGISTRATION FEE
  ====================================================================================================================
  
                                                                               Proposed Maximum
                                   Amounts to be      Proposed Maximum        Aggregate Offering         Amount of
                                    Registered   Offering Price Per Share (1)     Price(1)          Registration Fee
  --------------------------------------------------------------------------------------------------------------------
  Common Stock issuable pursuant
  to the 2000 Employee Stock         500,000              $5.6875                 $2,843,750             $750.75
  Purchase Plan
  ====================================================================================================================
  (1)  The Proposed Maximum Offering Price Per Share and the Proposed Aggregate
       Offering Price are based upon the average of the high and low prices for
       the Registrant's Common Stock, par value $.001 per share, as reported on
       the Nasdaq National Market on November 30, 2000, in accordance with Rules
       457(h) and (c) under the Securities Act of 1933, as amended, and are
       utilized solely for the purpose of calculating the registration fee.
  2
                                       PART I
  
                INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS
  
  Item 1.  PLAN INFORMATION. *
  
  Item 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION. *
  
           * Information required by Part I to be contained in the Section 10(a)
  Prospectus is omitted from this Registration Statement in accordance with Rule
  428 under the Securities Act of 1933 (the "Securities Act") and the Introductory
  Note to Part I of Form S-8.
  
                                      PART II
  
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  Item 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.
  
           MCK Communications, Inc. (the "Registrant") hereby incorporates by
           reference the following documents which have previously been filed with
           the Securities and Exchange Commission:
  
           (a)      the Registrant's Annual Report on Form 10-K for the fiscal
                    year ended April 30, 2000 filed with the Securities and
                    Exchange Commission on July 31, 2000 (File No. 000-32090);
  
           (b)      all other reports filed with the Securities and Exchange
                    Commission by the Registrant pursuant to Section 13(a) or
                    15(d) of the Securities Exchange Act of 1934, as amended (the
                    "Exchange Act") since April 30, 2000; and
  
           (c)      the description of the Registrant's Common Stock contained in
                    the Registration Statement on Form 8-A dated October 18, 1999
                    as filed with the Securities and Exchange Commission on
                    October 18, 1999 pursuant to Section 12(g) of the Securities
                    Exchange Act of 1934, as amended.
  
           In addition, all documents subsequently filed with the Securities and
  Exchange Commission by the Registrant pursuant to Sections 13(a), 13(c), 14 and
  15(d) of the Exchange Act, prior to the filing of a post-effective amendment
  hereto that indicates that all securities offered hereunder have been sold or
  which deregisters all securities then remaining unsold, shall be deemed to be
  incorporated by reference in this Registration Statement and to be a part hereof
  from the date of filing of such documents. Any statement contained in a document
  incorporated by reference herein shall be deemed to be modified or superseded
  for purposes hereof to the extent that a statement contained herein or in any
  subsequently filed document which also is incorporated by reference herein
  modifies or supersedes such statement. Any statement so modified or superseded
  shall not be deemed, except as so modified or superseded, to constitute a part
  of this Registration Statement.
  
  Item 4.  DESCRIPTION OF SECURITIES.
  
           Not Applicable.
  
  Item 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           Not Applicable.
  
  Item 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           In accordance with Section 145 of the General Corporation Law of the
  State of Delaware ("DGCL"), Article VII of the Registrant's Amended and Restated
  Certificate of Incorporation (the "Certificate") provides that no director of
  the Registrant shall be personally liable to the Registrant or its stockholders
  for monetary damages for breach of fiduciary duty as a director, except for
  liability (i) for any breach of the director's duty of loyalty to the Registrant
  or its stockholders, (ii) for acts or omissions not in good faith or which
  involve intentional misconduct or a knowing violation of law, (iii) in respect
  of intentional misconduct or a knowing violation of law, (iii) in respect of
  certain unlawful dividend payments or stock redemptions or repurchases, or (iv)
  for any transaction from which the director derived an improper personal
  benefit. In addition, the Certificate provides that if the DGCL is amended to
  authorize the further elimination or limitation of the personal liability of
  directors, then the liability of a director of the Registrant shall be
  eliminated or limited to the fullest extent permitted by the DGCL, as so
  amended.
  
           Article V of the Registrant's Amended and Restated By-laws (the
  "By-laws") provides for indemnification by the Registrant of its directors,
  officers and certain non-officer employees (including officers and certain
  non-officer employees of subsidiaries) under certain circumstances against
  expenses (including attorneys fees, judgments, fines and amounts paid in
  settlement) reasonably incurred in connection with the defense or settlement of
  any threatened, pending or completed legal proceeding in which any such person
  is involved by reason of the fact that such person is or was a director, an
  officer or an employee of the Registrant, or is acting in any capacity with
  other entities at the written request of the registrant, if such person acted in
  good faith and in a manner he or she reasonably believed to be in, or not
  opposed to, the best interests of the Registrant, and with respect to criminal
  actions or proceedings, that such person had no reasonable cause to believe his
  or her conduct was unlawful.
  
           Under Section 7 of the Underwriting Agreement filed as Exhibit 1.1 to
  the MCK Communications, Inc. Registration Statement on Form S-1 (File No.
  333-85821), the Underwriters have agreed to indemnify, under certain conditions,
  the Registrant, its directors, certain officers and persons who control the
  Registrant within the meaning of the Securities Act against certain liabilities.
  
           The Company carries directors' and officers' liability insurance
  covering its directors and officers.
  
  Item 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  Item 8.  EXHIBITS.
  
                                         2
  3
  
           The following is a complete list of exhibits filed or incorporated by
  reference as part of this Registration Statement.
  
  EXHIBITS
  --------
  
           5.1      Opinion of McDermott, Will & Emery as to the legality of the
                    securities being offered
  
           23.1     Consent of McDermott, Will & Emery (included in Exhibit 5.1)
  
           23.2     Consent of Ernst & Young LLP
  
           23.3     Powers of Attorney (included on signature pages to this
                    Registration Statement)
  
           99.1     2000 Employee Stock Purchase Plan of the Registrant
  
  ------------------------
  
  Item 9.  UNDERTAKINGS.
  
           (a)   The undersigned Registrant hereby undertakes:
  
                 (1)  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 acts 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.
                 Notwithstanding the foregoing, any increase or decrease in volume
                 of securities offered (if the total dollar value of securities
                 offered would not exceed that which was registered) and any
                 deviation from the low or high end of the estimated offering
                 range may be reflected in the form of prospectus filed with the
                 Commission pursuant to Rule 424(b) if, in the aggregate, the
                 changes in volume and price represent no more than a twenty
                 percent (20%) change in the maximum aggregate offering price set
                 forth in the "Calculation of Registration Fee" table in the
                 effective 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 (a)(1)(i) and (a)(1)(ii) herein do
           not apply if the Registration Statement is on Form S-3, Form S-8 or
           Form F-3, and the information required to be included in a
           post-effective amendment by those paragraphs is contained in periodic
           reports filed by the undersigned Registrant pursuant to Section 13 or
           Section 15 (d) of the Exchange Act that are incorporated by reference
           in the Registration Statement;
  
                 (2)  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; and
  
                 (3)  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.
  
           (b) The undersigned 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 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
  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.
  
           (c) 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.
  
                                         3
  4
  
           Pursuant to the requirements of the Securities Act, MCK Communications,
  Inc. 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 Newton, Massachusetts on November 30, 2000.
  
                                           MCK Communications, Inc.
  
                                           By: /s/ Steven J. Benson
                                              ----------------------------------
                                               Steven J. Benson
                                               Chairman, Chief Executive Officer
                                               and President
  
                                  POWER OF ATTORNEY
  
           KNOW ALL MEN BY THESE PRESENTS that each individual whose signature
  appears below constitutes and appoints each of Steven J. Benson and Paul K.
  Zurlo such person's true and lawful attorney-in-fact and agent with full power
  of substitution and resubstitution for such period and in such person's name,
  place and stead, in any and all capacities, to sign any and all amendments
  (including post-effective amendments) to this Registration Statement, and to
  file with same, with all exhibits thereto, and all documents in connection
  therewith, with the Securities and Exchange Commission, granting unto each said
  attorney-in-fact and agent full power and authority to do and perform each and
  every act and thing requisite and necessary to be done in and about the
  premises, as fully to all intents and purposes as such person might or could do
  in person, hereby ratifying and confirming all that any said attorney-in-fact
  and agent, or any substitute or substitutes of any of them, may lawfully do or
  cause to be done by virtue hereof.
  
           Pursuant to the requirements of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  SIGNATURE                   TITLE                                               DATE
  /s/ Steven J. Benson        Chairman of the Board, (Chief Executive         November 30, 2000
  -------------------------   Officer, President, Chairman and Director)
  Steven J. Benson
  
  /s/ Paul K. Zurlo           Chief Financial Officer (Principal Financial    November 30, 2000
  -------------------------   and Accounting Officer)
  Paul K. Zurlo
  
                              Director
  -------------------------
  Calvin K. Manz
  
  /s/ John B. Landry          Director                                        November 30, 2000
  -------------------------
  John B. Landry
  
  /s/ Gregory M. Avis         Director                                        November 30, 2000
  -------------------------
  Gregory M. Avis
  
  /s/ Michael H. Balmuth      Director                                        November 30, 2000
  -------------------------
  Michael H. Balmuth
  
                              Director
  -------------------------
  Paul Severino
  4
  5
  
                                    EXHIBIT INDEX
  
  EXHIBITS
  --------
  
    5.1     Opinion of McDermott, Will & Emery as to the legality of the
            securities being offered
  
   23.1     Consent of McDermott, Will & Emery (included in Exhibit 5.1)
  
   23.2     Consent of Ernst & Young LLP
  
   23.3     Powers of Attorney (included on signature pages to this Registration
            Statement)
  
   99.1     2000 Employee Stock Purchase Plan of the Registrant
  
  ----------------
  
                                         5