content: <PAGE>
  
     As filed with the Securities and Exchange Commission on September 18, 2002
  
                                                              File No. 333-_______
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                      FORM S-8
  
                               REGISTRATION STATEMENT
  
                                        Under
  
                             THE SECURITIES ACT OF 1933
  
                              FORRESTER RESEARCH, INC.
               (Exact name of registrant as specified in its charter)
  
             DELAWARE                                            04-2797789
   (State or other jurisdiction                               (I.R.S. Employer
  of incorporation or organization)                           Identification No.)
  
  
                                400 Technology Square
                           Cambridge, Massachusetts 02139
                                   (617) 497-7090
            (Address of principal executive offices, including zip code)
  
                          1996 EMPLOYEE STOCK PURCHASE PLAN
  
                           -----------------------------
                              (Full title of the plan)
  
                              TIMOTHY J. MOYNIHAN, ESQ.
                            General Counsel and Secretary
                              Forrester Research, Inc.
                                400 Technology Square
                           Cambridge, Massachusetts 02139
                                   (617) 497-7090
                                (617) 868-0577 (Fax)
  
  
                  ------------------------------------------------
  (Name, Address and Telephone Number, including Area Code, of Agent for Service)
  
  
                           CALCULATION OF REGISTRATION FEE
  
  <TABLE>
  <CAPTION>
  ====================================================================================================================
  
   Title of Securities        Amount to be         Proposed maximum          Proposed maximum        Amount of
   to be registered           registered           offering price            aggregate offering      registration fee
                                                   per share(1)              price(1)
  --------------------------------------------------------------------------------------------------------------------
  <S>                         <C>                      <C>                      <C>                      <C>
  Common Stock,
  par value $0.01             500,000 shares           $16.11                   $8,055,000               $742
  ====================================================================================================================
  </TABLE>
  
  (1)  The offering price per share and the maximum aggregate offering price have
       been estimated solely for the purpose of determining the registration fee
       pursuant to Rule 457(h) on the basis of the average of the high and low
       prices of Forrester Research, Inc. Common Stock, par value $0.01 per share,
       reported on the Nasdaq National Market on September 17, 2002.
  
  ================================================================================
  
  
  <PAGE>
  
  
  
                                  EXPLANATORY NOTE
  
  
       This Registration Statement has been filed pursuant to General Instruction
  E on Form S-8, to register 500,000 additional shares of common stock to be
  offered pursuant to the 1996 Employee Stock Purchase Plan (the "1996 Plan") of
  Forrester Research, Inc. (the "Company"). A registration statement on Form S-8
  (No. 333-16905), filed with the Commission on November 27, 1996 to register
  400,000 shares of common stock offered pursuant to the 1996 Plan is currently
  effective and is hereby incorporated herein by reference.
  
       All references to shares of Company common stock have been adjusted to
  reflect the stock split effected in the form of a 100% stock dividend on
  February 7, 2000.
  
  
  
                                        -2-
  
  
  <PAGE>
  
                                     SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, 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 on Form S-8 to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Cambridge, The Commonwealth of Massachusetts, on
  this 18th day of September, 2002.
  
                                         FORRESTER RESEARCH, INC.
  
  
                                         By: /s/ George F. Colony
                                            ----------------------------------
                                             Name: George F. Colony
                                             Title: Chairman of the Board and
                                                    Chief Executive Officer
  
  
                                  POWER OF ATTORNEY
  
       Pursuant to the requirement of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated. Each person whose signature appears below
  hereby authorizes and constitutes George F. Colony, Warren Hadley and Timothy J.
  Moynihan with full power of substitution, to execute in the name of and on
  behalf of such person any amendment (including any post-effective amendment) to
  this Registration Statement, and any subsequent registration statement for the
  same offering that may be filed under Rule 462(b) under the Securities Act, and
  to file the same, with exhibits thereto, and other documents in connection
  therewith, making such changes in this Registration Statement and any subsequent
  registration statement under Rule 462(b) as the person(s) so acting deems
  appropriate.
  
  Signature                 Title                               Date
  ---------                 -----                               ----
  
  
  /s/ George F. Colony      Chairman of the Board and Chief     September 18, 2002
  -----------------------   Executive Officer (principal
  George F. Colony          executive officer)
  
  
  /s/ Warren Hadley         Chief Financial Officer and         September 18, 2002
  -----------------------   Treasurer (principal financial
  Warren Hadley             and accounting officer)
  
  
  /s/ Robert M. Galford     Director                            September 18, 2002
  -----------------------
  Robert M. Galford
  
  /s/ George R. Hornig      Director                            September 18, 2002
  -----------------------
  George R. Hornig
  
  
                                        -3-
  
  <PAGE>
  /s/ Michael H. Welles     Director                         September 18, 2002
  -----------------------
  Michael H. Welles
  
  
  /s/ Henk W. Broeders      Director                         September 18, 2002
  ----------------------
  Henk W. Broeders
  
  
                                        -4-
  <PAGE>
                                   EXHIBIT INDEX
  
  <Table>
  <Caption>
  Number    Title of Exhibit                                  Page
  ------    ----------------                                  ----
  
  <S>       <C>                                               <C>
   5        Opinion of Ropes & Gray                           6
  
  23.1      Notice Regarding Consent of Arthur Andersen LLP   7
  
  23.2      Consent of Ropes & Gray (contained
            in the opinion filed as Exhibit 5 hereto)         6
  
  24        Power of Attorney (included as part of
            the signature page filed herewith)                3
  </Table>
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "b44191ppsv8.txt", "description": "FORRESTER RESEARCH INC.", "secsgml_size_bytes": 7604}]
metadata_filer: {"company-data": {"conformed-name": "FORRESTER RESEARCH INC", "cik": "0001023313", "assigned-sic": "8700", "irs-number": "042797789", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-99749", "film-number": "02767228"}, "business-address": {"street1": "400 TECHNOLOGY SQUARE", "city": "CAMBRIDGE", "state": "MA", "zip": "02139", "phone": "6174977090"}, "mail-address": {"street1": "400 TECHNOLOGY SQUARE", "city": "CAMBRIDGE", "state": "MA", "zip": "02139"}}
text: As filed with the Securities and Exchange Commission on September 18, 2002
  
                                                              File No. 333-_______
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                      FORM S-8
  
                               REGISTRATION STATEMENT
  
                                        Under
  
                             THE SECURITIES ACT OF 1933
  
                              FORRESTER RESEARCH, INC.
               (Exact name of registrant as specified in its charter)
  
             DELAWARE                                            04-2797789
   (State or other jurisdiction                               (I.R.S. Employer
  of incorporation or organization)                           Identification No.)
  
                                400 Technology Square
                           Cambridge, Massachusetts 02139
                                   (617) 497-7090
            (Address of principal executive offices, including zip code)
  
                          1996 EMPLOYEE STOCK PURCHASE PLAN
  
                           -----------------------------
                              (Full title of the plan)
  
                              TIMOTHY J. MOYNIHAN, ESQ.
                            General Counsel and Secretary
                              Forrester Research, Inc.
                                400 Technology Square
                           Cambridge, Massachusetts 02139
                                   (617) 497-7090
                                (617) 868-0577 (Fax)
  
                  ------------------------------------------------
  (Name, Address and Telephone Number, including Area Code, of Agent for Service)
  
                           CALCULATION OF REGISTRATION FEE
  ====================================================================================================================
  
   Title of Securities        Amount to be         Proposed maximum          Proposed maximum        Amount of
   to be registered           registered           offering price            aggregate offering      registration fee
                                                   per share(1)              price(1)
  --------------------------------------------------------------------------------------------------------------------
  Common Stock,
  par value $0.01             500,000 shares           $16.11                   $8,055,000               $742
  ====================================================================================================================
  (1)  The offering price per share and the maximum aggregate offering price have
       been estimated solely for the purpose of determining the registration fee
       pursuant to Rule 457(h) on the basis of the average of the high and low
       prices of Forrester Research, Inc. Common Stock, par value $0.01 per share,
       reported on the Nasdaq National Market on September 17, 2002.
  
  ================================================================================
  EXPLANATORY NOTE
  
       This Registration Statement has been filed pursuant to General Instruction
  E on Form S-8, to register 500,000 additional shares of common stock to be
  offered pursuant to the 1996 Employee Stock Purchase Plan (the "1996 Plan") of
  Forrester Research, Inc. (the "Company"). A registration statement on Form S-8
  (No. 333-16905), filed with the Commission on November 27, 1996 to register
  400,000 shares of common stock offered pursuant to the 1996 Plan is currently
  effective and is hereby incorporated herein by reference.
  
       All references to shares of Company common stock have been adjusted to
  reflect the stock split effected in the form of a 100% stock dividend on
  February 7, 2000.
  
                                        -2-
  SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, 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 on Form S-8 to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Cambridge, The Commonwealth of Massachusetts, on
  this 18th day of September, 2002.
  
                                         FORRESTER RESEARCH, INC.
  
                                         By: /s/ George F. Colony
                                            ----------------------------------
                                             Name: George F. Colony
                                             Title: Chairman of the Board and
                                                    Chief Executive Officer
  
                                  POWER OF ATTORNEY
  
       Pursuant to the requirement of the Securities Act of 1933, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated. Each person whose signature appears below
  hereby authorizes and constitutes George F. Colony, Warren Hadley and Timothy J.
  Moynihan with full power of substitution, to execute in the name of and on
  behalf of such person any amendment (including any post-effective amendment) to
  this Registration Statement, and any subsequent registration statement for the
  same offering that may be filed under Rule 462(b) under the Securities Act, and
  to file the same, with exhibits thereto, and other documents in connection
  therewith, making such changes in this Registration Statement and any subsequent
  registration statement under Rule 462(b) as the person(s) so acting deems
  appropriate.
  
  Signature                 Title                               Date
  ---------                 -----                               ----
  
  /s/ George F. Colony      Chairman of the Board and Chief     September 18, 2002
  -----------------------   Executive Officer (principal
  George F. Colony          executive officer)
  
  /s/ Warren Hadley         Chief Financial Officer and         September 18, 2002
  -----------------------   Treasurer (principal financial
  Warren Hadley             and accounting officer)
  
  /s/ Robert M. Galford     Director                            September 18, 2002
  -----------------------
  Robert M. Galford
  
  /s/ George R. Hornig      Director                            September 18, 2002
  -----------------------
  George R. Hornig
  
                                        -3-
  /s/ Michael H. Welles     Director                         September 18, 2002
  -----------------------
  Michael H. Welles
  
  /s/ Henk W. Broeders      Director                         September 18, 2002
  ----------------------
  Henk W. Broeders
  
                                        -4-
  EXHIBIT INDEX
  Number    Title of Exhibit                                  Page
  ------    ----------------                                  ----
  5        Opinion of Ropes & Gray                           6
  
  23.1      Notice Regarding Consent of Arthur Andersen LLP   7
  
  23.2      Consent of Ropes & Gray (contained
            in the opinion filed as Exhibit 5 hereto)         6
  
  24        Power of Attorney (included as part of
            the signature page filed herewith)                3