content: <PAGE>   1
  As filed with the Securities and Exchange Commission on June 28, 2000
  
                                                       Registration No. 333-______
  ================================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                             --------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        under
                             THE SECURITIES ACT OF 1933
  
                          PAREXEL International Corporation
               (Exact name of registrant as specified in its charter)
  
           Massachusetts                                  04-2776269
  (State or other jurisdiction of                     (I.R.S. Employer
   incorporation or organization)                     Identification No.)
  
  
                         195 West Street, Waltham, MA 02451
                 (Address of principal executive offices) (Zip Code)
  
                                --------------------
  
                          PAREXEL INTERNATIONAL CORPORATION
                                   1995 Stock Plan
                              (Full title of the plan)
  
                               Josef H. von Rickenbach
                        Chief Executive Officer and Chairman
                          PAREXEL International Corporation
                                   195 West Street
                            Waltham, Massachusetts 02451
                       (Name and address of agent for service)
  
                                   (781) 487-9900
            (Telephone number, including area code of agent for service)
  
                                --------------------
  
                                     Copies to:
                               Mark T. Beaudouin, Esq.
                         Vice President and General Counsel
                          PAREXEL International Corporation
                                   195 West Street
                            Waltham, Massachusetts 02451
  
                                --------------------
  
                           Calculation Of Registration Fee
  <TABLE>
  <CAPTION>
  
  =============================================================================================================
  Title of Securities       Amount to be         Proposed maximum        Proposed Maximum          Amount of
    to be registered         registered         offering price per      Aggregate offering     registration fee
                                                       share                  price
  -------------------------------------------------------------------------------------------------------------
   <S>                      <C>                      <C>                    <C>                   <C>
  
    Common Stock,
    $.01 par value        800,000 shares            $9.125                  $7,300,000             $1,928
  =============================================================================================================
  </TABLE>
  
  
  (1)  The price of $9.125 per share, which is the average of the high and low
       price per share of the Common Stock as reported on the Nasdaq National
       Market on June 26, 2000, is set forth solely for purposes of calculating
       the filing fee pursuant to Rules 457(c) and 457(h).
  ================================================================================
  
  
  
  <PAGE>   2
  
  
  
                       STATEMENT OF INCORPORATION BY REFERENCE
  
       This Registration Statement registers additional securities of the same
  class as other securities for which the Registration Statement No. 33-80301 on
  Form S-8, as filed with the Securities and Exchange Commission on December 12,
  1995, relating to the PAREXEL International Corporation Second Amended and
  Restated 1995 Stock Plan, is effective. Pursuant to General Instruction E, the
  contents of the above-listed Registration Statement are hereby incorporated by
  reference.
  
  
  
  
  
  <PAGE>   3
                                     SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, as amended, 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 City of Waltham, Commonwealth of Massachusetts on June 27,
  2000.
  
  
                                       PAREXEL INTERNATIONAL CORPORATION
  
  
                                       By: /s/ Josef H. von Rickenbach
                                           --------------------------------------
                                           Josef H. von Rickenbach
                                           Chief Executive Officer and Chairman
  
  
                          POWER OF ATTORNEY AND SIGNATURES
  
       We, the undersigned officers and directors of PAREXEL International
  Corporation, hereby severally constitute and appoint Josef H. von Rickenbach,
  James F. Winschel and Mark T. Beaudouin and each of them singly, as true and
  lawful attorneys, with full power to them and each of them singly, to sign for
  us in our names in the capacities indicated below, any and all pre-effective and
  post-effective amendments to this Registration Statement on Form S-8, and
  generally to do all things in our names and on our behalf in such capacities to
  enable PAREXEL International Corporation to comply with the provisions of the
  Securities Act of 1933, as amended, and all requirements of the Securities and
  Exchange Commission.
  
       Pursuant to the requirements of the Securities Act of 1933, as amended,
  this Registration Statement has been signed below by the following persons on
  behalf of the Registrant and in the capacities and on the dates indicated.
  
  
  SIGNATURE                       TITLE(S)                        DATE
  ---------                       --------                        ----
  
  /s/ Josef H. von Rickenbach     Chief Executive Officer         June 27, 2000
  ---------------------------     and Chairman
  Josef H. von Rickenbach         (principal executive officer)
  
  
  /s/ James F. Winschel           Senior Vice President and       June 27, 2000
  ---------------------------     Chief Financial Officer
  James F. Winschel               (principal financial and
                                  accounting officer)
  
  
  /s/ A. Dana Callow, Jr.         Director                        June 27, 2000
  ---------------------------
  A. Dana Callow, Jr.
  
  
  /s/ A. Joseph Eagle             Director                        June 27, 2000
  ---------------------------
  A. Joseph Eagle
  
  
  /s/ Patrick J. Fortune          Director                        June 27, 2000
  ---------------------------
  Patrick J. Fortune
  
  
  /s/ Werner M. Herrmann          Director                        June 27, 2000
  ---------------------------
  Werner M. Herrmann
  
  
  /s/ William T. Sobo             Director                        June 27, 2000
  ---------------------------
  William T. Sobo
  
  
  /s/ Serge Okun                  Director                        June 27, 2000
  ---------------------------
  Serge Okun
  <PAGE>   4
  
  
  
                                    EXHIBIT INDEX
  
  
  EXHIBIT NO.       DESCRIPTION OF EXHIBIT
  -----------       ----------------------
  
  Exhibit 4.1       Amended and Restated Articles of Incorporation of the
                    Registrant (filed as Exhibit 3.1 to the Registrant's Quarterly
                    Report on Form 10-Q for the Quarter Ended December 31, 1996
                    and incorporated herein by this reference).
  
  Exhibit 4.2       Amended and Restated By-Laws of the Registrant (filed as
                    Exhibit 3.2 to the Registrant's Registration Statement on
                    Form S-1 (File  No. 333-1188) and incorporated herein by this
                    reference).
  
  Exhibit 4.3       Specimen certificate representing the Common Stock of the
                    Registrant (filed as Exhibit 3.1 to the Registrant's Quarterly
                    Report on Form 10-Q for the Quarter Ended December 31, 1996
                    and incorporated herein by this reference).
  
  Exhibit 5.1       Opinion of Hale and Dorr, LLP.
  
  Exhibit 23.1      Consent of PricewaterhouseCoopers LLP.
  
  Exhibit 23.2      Consent of Hale and Dorr, LLP (included in Exhibit 5.1).
  
  Exhibit 24.1      Power of Attorney (included as part of the signature page to
                    this Registration Statement).
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "s-8.txt", "description": "PAREXEL INTERNATIONAL CORPORATION", "secsgml_size_bytes": 8496}]
metadata_filer: {"company-data": {"conformed-name": "PAREXEL INTERNATIONAL CORP", "cik": "0000799729", "assigned-sic": "8731", "irs-number": "042776269", "state-of-incorporation": "MA", "fiscal-year-end": "0630"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-40276", "film-number": "662759"}, "business-address": {"street1": "195 WEST ST", "city": "WALTHAM", "state": "MA", "zip": "02151", "phone": "7814879900"}, "mail-address": {"street1": "195 WEST ST", "city": "WALTHAM", "state": "MA", "zip": "02154"}}
text: 1
  As filed with the Securities and Exchange Commission on June 28, 2000
  
                                                       Registration No. 333-______
  ================================================================================
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                             --------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                        under
                             THE SECURITIES ACT OF 1933
  
                          PAREXEL International Corporation
               (Exact name of registrant as specified in its charter)
  
           Massachusetts                                  04-2776269
  (State or other jurisdiction of                     (I.R.S. Employer
   incorporation or organization)                     Identification No.)
  
                         195 West Street, Waltham, MA 02451
                 (Address of principal executive offices) (Zip Code)
  
                                --------------------
  
                          PAREXEL INTERNATIONAL CORPORATION
                                   1995 Stock Plan
                              (Full title of the plan)
  
                               Josef H. von Rickenbach
                        Chief Executive Officer and Chairman
                          PAREXEL International Corporation
                                   195 West Street
                            Waltham, Massachusetts 02451
                       (Name and address of agent for service)
  
                                   (781) 487-9900
            (Telephone number, including area code of agent for service)
  
                                --------------------
  
                                     Copies to:
                               Mark T. Beaudouin, Esq.
                         Vice President and General Counsel
                          PAREXEL International Corporation
                                   195 West Street
                            Waltham, Massachusetts 02451
  
                                --------------------
  
                           Calculation Of Registration Fee
  =============================================================================================================
  Title of Securities       Amount to be         Proposed maximum        Proposed Maximum          Amount of
    to be registered         registered         offering price per      Aggregate offering     registration fee
                                                       share                  price
  -------------------------------------------------------------------------------------------------------------
  Common Stock,
    $.01 par value        800,000 shares            $9.125                  $7,300,000             $1,928
  =============================================================================================================
  (1)  The price of $9.125 per share, which is the average of the high and low
       price per share of the Common Stock as reported on the Nasdaq National
       Market on June 26, 2000, is set forth solely for purposes of calculating
       the filing fee pursuant to Rules 457(c) and 457(h).
  ================================================================================
  2
  
                       STATEMENT OF INCORPORATION BY REFERENCE
  
       This Registration Statement registers additional securities of the same
  class as other securities for which the Registration Statement No. 33-80301 on
  Form S-8, as filed with the Securities and Exchange Commission on December 12,
  1995, relating to the PAREXEL International Corporation Second Amended and
  Restated 1995 Stock Plan, is effective. Pursuant to General Instruction E, the
  contents of the above-listed Registration Statement are hereby incorporated by
  reference.
  3
                                     SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, as amended, 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 City of Waltham, Commonwealth of Massachusetts on June 27,
  2000.
  
                                       PAREXEL INTERNATIONAL CORPORATION
  
                                       By: /s/ Josef H. von Rickenbach
                                           --------------------------------------
                                           Josef H. von Rickenbach
                                           Chief Executive Officer and Chairman
  
                          POWER OF ATTORNEY AND SIGNATURES
  
       We, the undersigned officers and directors of PAREXEL International
  Corporation, hereby severally constitute and appoint Josef H. von Rickenbach,
  James F. Winschel and Mark T. Beaudouin and each of them singly, as true and
  lawful attorneys, with full power to them and each of them singly, to sign for
  us in our names in the capacities indicated below, any and all pre-effective and
  post-effective amendments to this Registration Statement on Form S-8, and
  generally to do all things in our names and on our behalf in such capacities to
  enable PAREXEL International Corporation to comply with the provisions of the
  Securities Act of 1933, as amended, and all requirements of the Securities and
  Exchange Commission.
  
       Pursuant to the requirements of the Securities Act of 1933, as amended,
  this Registration Statement has been signed below by the following persons on
  behalf of the Registrant and in the capacities and on the dates indicated.
  
  SIGNATURE                       TITLE(S)                        DATE
  ---------                       --------                        ----
  
  /s/ Josef H. von Rickenbach     Chief Executive Officer         June 27, 2000
  ---------------------------     and Chairman
  Josef H. von Rickenbach         (principal executive officer)
  
  /s/ James F. Winschel           Senior Vice President and       June 27, 2000
  ---------------------------     Chief Financial Officer
  James F. Winschel               (principal financial and
                                  accounting officer)
  
  /s/ A. Dana Callow, Jr.         Director                        June 27, 2000
  ---------------------------
  A. Dana Callow, Jr.
  
  /s/ A. Joseph Eagle             Director                        June 27, 2000
  ---------------------------
  A. Joseph Eagle
  
  /s/ Patrick J. Fortune          Director                        June 27, 2000
  ---------------------------
  Patrick J. Fortune
  
  /s/ Werner M. Herrmann          Director                        June 27, 2000
  ---------------------------
  Werner M. Herrmann
  
  /s/ William T. Sobo             Director                        June 27, 2000
  ---------------------------
  William T. Sobo
  
  /s/ Serge Okun                  Director                        June 27, 2000
  ---------------------------
  Serge Okun
  4
  
                                    EXHIBIT INDEX
  
  EXHIBIT NO.       DESCRIPTION OF EXHIBIT
  -----------       ----------------------
  
  Exhibit 4.1       Amended and Restated Articles of Incorporation of the
                    Registrant (filed as Exhibit 3.1 to the Registrant's Quarterly
                    Report on Form 10-Q for the Quarter Ended December 31, 1996
                    and incorporated herein by this reference).
  
  Exhibit 4.2       Amended and Restated By-Laws of the Registrant (filed as
                    Exhibit 3.2 to the Registrant's Registration Statement on
                    Form S-1 (File  No. 333-1188) and incorporated herein by this
                    reference).
  
  Exhibit 4.3       Specimen certificate representing the Common Stock of the
                    Registrant (filed as Exhibit 3.1 to the Registrant's Quarterly
                    Report on Form 10-Q for the Quarter Ended December 31, 1996
                    and incorporated herein by this reference).
  
  Exhibit 5.1       Opinion of Hale and Dorr, LLP.
  
  Exhibit 23.1      Consent of PricewaterhouseCoopers LLP.
  
  Exhibit 23.2      Consent of Hale and Dorr, LLP (included in Exhibit 5.1).
  
  Exhibit 24.1      Power of Attorney (included as part of the signature page to
                    this Registration Statement).