content: <PAGE>   1
  
       AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 13, 2001
                                                        REGISTRATION NO. 333-
  ================================================================================
  
                                    UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                                ---------------------
  
                                      FORM S-8
  
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                                ---------------------
  
                        CHARLES RIVER ASSOCIATES INCORPORATED
               (Exact name of registrant as specified in its charter)
  
  MASSACHUSETTS                                                   04-2372210
  (State or other jurisdiction of                             (I.R.S. employer
  incorporation or organization)                             identification no.)
  
  200 CLARENDON STREET, BOSTON, MASSACHUSETTS                      02116
  (Address of principal executive offices)                      (Zip code)
  
                        CHARLES RIVER ASSOCIATES INCORPORATED
                  1998 INCENTIVE AND NONQUALIFIED STOCK OPTION PLAN
                              (Full title of the plan)
  
                                --------------------
  
                                  JAMES C. BURROWS
                        CHARLES RIVER ASSOCIATES INCORPORATED
                                200 CLARENDON STREET
                             BOSTON, MASSACHUSETTS 02116
                       (Name and address of agent for service)
  
                                   (617) 425-3000
            (Telephone number, including area code, of agent for service)
  
                                --------------------
  
                                   WITH COPIES TO:
                              PETER M. ROSENBLUM, ESQ.
                                JOHN D. HANCOCK, ESQ.
                               FOLEY, HOAG & ELIOT LLP
                               ONE POST OFFICE SQUARE
                             BOSTON, MASSACHUSETTS 02109
                                   (617) 832-1000
  
                                --------------------
  
                           CALCULATION OF REGISTRATION FEE
  
  <TABLE>
  <CAPTION>
  
  ========================================================================================
      TITLE OF            AMOUNT        PROPOSED MAXIMUM   PROPOSED MAXIMUM    AMOUNT OF
  SECURITIES TO BE        TO BE          OFFERING PRICE        AGGREGATE      REGISTRATION
     REGISTERED         REGISTERED         PER SHARE        OFFERING PRICE        FEE
  ----------------------------------------------------------------------------------------
  <S>                <C>                    <C>                <C>               <C>
  common stock,
    no par value     271,900 shares(1)      $10.34(2)         $2,811,446        $  703
  ----------------------------------------------------------------------------------------
  common stock,
    no par value     628,100 shares(3)      $14.63(4)         $9,189,103        $2,298
  ----------------------------------------------------------------------------------------
    Total ..............................................................        $3,001
  ========================================================================================
  </TABLE>
  
  (1)  Represents shares of common stock issuable upon exercise of stock options
       outstanding under the Charles River Associates Incorporated 1998 Incentive
       and Nonqualified Stock Option Plan, as amended.
  
  (2)  Calculated pursuant to Rule 457(h)(1) under the Securities Act of 1933
       based on the weighted average exercise price per share of the options
       outstanding under the stock option plan.
  
  (3)  Represents shares of common stock issuable upon exercise of stock options
       available for grant pursuant to the stock option plan.
  
  (4)  Calculated pursuant to Rules 457(c) and (h)(1) under the Securities Act of
       1933 based on the average of the high and low sale prices of the common
       stock as reported on the Nasdaq National Market on June 11, 2001.
  
  <PAGE>   2
       This registration statement covers 900,000 shares of common stock issuable
  pursuant to our 1998 Incentive and Nonqualified Stock Option Plan. These shares
  are in addition to the 970,000 shares of common stock registered pursuant to the
  registration statement on Form S-8, File No. 333-63451, which we filed with the
  Securities and Exchange Commission on September 15, 1998.
  
       The contents of our registration statement on Form S-8, File No. 333-63451,
  are incorporated herein by reference.
  
  
  <PAGE>   3
  ITEM 8. EXHIBITS.
  
  EXHIBIT
  NUMBER      DESCRIPTION
  --------    -----------
  
     5.1      Opinion of Foley, Hoag & Eliot LLP.
    23.1      Consent of Ernst & Young LLP, independent auditors.
    23.2      Consent of Foley, Hoag & Eliot LLP (included in Exhibit 5.1).
    24.1      Power of attorney (contained on the signature page of this
              registration statement).
  <PAGE>   4
                                     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 to be signed on its behalf by the undersigned, thereunto duly
  authorized, in Boston, Massachusetts, as of June 13, 2001
  
                                         CHARLES RIVER ASSOCIATES INCORPORATED
  
                                         By: /s/ James C. Burrows
                                             -----------------------------------
                                             James C. Burrows
                                             President and Chief Executive Officer
  
  
                                  POWER OF ATTORNEY
  
       KNOW ALL BY THESE PRESENTS that each individual whose signature appears
  below hereby constitutes and appoints James C. Burrows and Marybeth Celorier,
  and each of them, his or her true and lawful attorneys-in-fact and agents with
  full power of substitution, for him or her and in his or her 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 the same,
  with all exhibits thereto, and all documents in connection therewith, with the
  Securities and Exchange Commission, granting unto said attorneys-in-fact and
  agents, and each of them, full power and authority to do and perform each and
  every act and thing which they, or any of them, may deem necessary or advisable
  to be done in connection with this registration statement, as fully to all
  intents and purposes as he or she might or could do in person, hereby ratifying
  and confirming all that said attorneys-in-fact and agents or any of them, or any
  substitute or substitutes for him or her, or any or all of them, may lawfully do
  or cause to be done by virtue hereof.
  
       Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  as of June 13, 2001.
  
            SIGNATURE                     TITLE
            ---------                     -----
  
  /s/ Franklin M. Fisher          Chairman of the Board
  ----------------------------
  Franklin M. Fisher
  
  
  /s/ James C. Burrows            President, Chief Executive Officer and Director
  ----------------------------   (Principal Executive Officer)
  James C. Burrows
  
  
  /s/ Marybeth Celorier           Vice President and Treasurer
  ----------------------------   (Principal Financial and Accounting Officer)
  Marybeth Celorier
  
  <PAGE>   5
  /s/ William F. Concannon        Director
  ----------------------------
  William F. Concannon
  
  
  /s/ Carl Kaysen                 Director
  ----------------------------
  Carl Kaysen
  
  
  /s/ Rowland T. Moriarty         Director
  ----------------------------
  Rowland T. Moriarty
  
  
  /s/ J. Robert S. Prichard       Director
  ----------------------------
  J. Robert S. Prichard
  
  
  /s/ Steven C. Salop             Director
  ----------------------------
  Steven C. Salop
  
  
  /s/ Carl B. Shapiro             Director
  ----------------------------
  Carl B. Shapiro
  
  <PAGE>   6
                                   EXHIBIT INDEX
  
  EXHIBIT
  NUMBER      DESCRIPTION
  -------     -----------
  
     5.1      Opinion of Foley, Hoag & Eliot LLP.
    23.1      Consent of Ernst & Young LLP, independent auditors.
    23.2      Consent of Foley, Hoag & Eliot LLP (included in Exhibit 5.1).
    24.1      Power of attorney (contained on the signature page of this
              registration statement).
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "b39657crs-8.txt", "description": "CHARLES RIVER ASSOCIATES", "secsgml_size_bytes": 8761}]
metadata_filer: {"company-data": {"conformed-name": "CHARLES RIVER ASSOCIATES INC", "cik": "0001053706", "assigned-sic": "8111", "irs-number": "042372210", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-62910", "film-number": "1660072"}, "business-address": {"street1": "200 CLARENDON STREET", "street2": "T-33", "city": "BOSTON", "state": "MA", "zip": "02116", "phone": "6174253000"}}
text: 1
  
       AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 13, 2001
                                                        REGISTRATION NO. 333-
  ================================================================================
  
                                    UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                                ---------------------
  
                                      FORM S-8
  
                               REGISTRATION STATEMENT
                                        UNDER
                             THE SECURITIES ACT OF 1933
  
                                ---------------------
  
                        CHARLES RIVER ASSOCIATES INCORPORATED
               (Exact name of registrant as specified in its charter)
  
  MASSACHUSETTS                                                   04-2372210
  (State or other jurisdiction of                             (I.R.S. employer
  incorporation or organization)                             identification no.)
  
  200 CLARENDON STREET, BOSTON, MASSACHUSETTS                      02116
  (Address of principal executive offices)                      (Zip code)
  
                        CHARLES RIVER ASSOCIATES INCORPORATED
                  1998 INCENTIVE AND NONQUALIFIED STOCK OPTION PLAN
                              (Full title of the plan)
  
                                --------------------
  
                                  JAMES C. BURROWS
                        CHARLES RIVER ASSOCIATES INCORPORATED
                                200 CLARENDON STREET
                             BOSTON, MASSACHUSETTS 02116
                       (Name and address of agent for service)
  
                                   (617) 425-3000
            (Telephone number, including area code, of agent for service)
  
                                --------------------
  
                                   WITH COPIES TO:
                              PETER M. ROSENBLUM, ESQ.
                                JOHN D. HANCOCK, ESQ.
                               FOLEY, HOAG & ELIOT LLP
                               ONE POST OFFICE SQUARE
                             BOSTON, MASSACHUSETTS 02109
                                   (617) 832-1000
  
                                --------------------
  
                           CALCULATION OF REGISTRATION FEE
  ========================================================================================
      TITLE OF            AMOUNT        PROPOSED MAXIMUM   PROPOSED MAXIMUM    AMOUNT OF
  SECURITIES TO BE        TO BE          OFFERING PRICE        AGGREGATE      REGISTRATION
     REGISTERED         REGISTERED         PER SHARE        OFFERING PRICE        FEE
  ----------------------------------------------------------------------------------------
  common stock,
    no par value     271,900 shares(1)      $10.34(2)         $2,811,446        $  703
  ----------------------------------------------------------------------------------------
  common stock,
    no par value     628,100 shares(3)      $14.63(4)         $9,189,103        $2,298
  ----------------------------------------------------------------------------------------
    Total ..............................................................        $3,001
  ========================================================================================
  (1)  Represents shares of common stock issuable upon exercise of stock options
       outstanding under the Charles River Associates Incorporated 1998 Incentive
       and Nonqualified Stock Option Plan, as amended.
  
  (2)  Calculated pursuant to Rule 457(h)(1) under the Securities Act of 1933
       based on the weighted average exercise price per share of the options
       outstanding under the stock option plan.
  
  (3)  Represents shares of common stock issuable upon exercise of stock options
       available for grant pursuant to the stock option plan.
  
  (4)  Calculated pursuant to Rules 457(c) and (h)(1) under the Securities Act of
       1933 based on the average of the high and low sale prices of the common
       stock as reported on the Nasdaq National Market on June 11, 2001.
  2
       This registration statement covers 900,000 shares of common stock issuable
  pursuant to our 1998 Incentive and Nonqualified Stock Option Plan. These shares
  are in addition to the 970,000 shares of common stock registered pursuant to the
  registration statement on Form S-8, File No. 333-63451, which we filed with the
  Securities and Exchange Commission on September 15, 1998.
  
       The contents of our registration statement on Form S-8, File No. 333-63451,
  are incorporated herein by reference.
  3
  ITEM 8. EXHIBITS.
  
  EXHIBIT
  NUMBER      DESCRIPTION
  --------    -----------
  
     5.1      Opinion of Foley, Hoag & Eliot LLP.
    23.1      Consent of Ernst & Young LLP, independent auditors.
    23.2      Consent of Foley, Hoag & Eliot LLP (included in Exhibit 5.1).
    24.1      Power of attorney (contained on the signature page of this
              registration statement).
  4
                                     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 to be signed on its behalf by the undersigned, thereunto duly
  authorized, in Boston, Massachusetts, as of June 13, 2001
  
                                         CHARLES RIVER ASSOCIATES INCORPORATED
  
                                         By: /s/ James C. Burrows
                                             -----------------------------------
                                             James C. Burrows
                                             President and Chief Executive Officer
  
                                  POWER OF ATTORNEY
  
       KNOW ALL BY THESE PRESENTS that each individual whose signature appears
  below hereby constitutes and appoints James C. Burrows and Marybeth Celorier,
  and each of them, his or her true and lawful attorneys-in-fact and agents with
  full power of substitution, for him or her and in his or her 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 the same,
  with all exhibits thereto, and all documents in connection therewith, with the
  Securities and Exchange Commission, granting unto said attorneys-in-fact and
  agents, and each of them, full power and authority to do and perform each and
  every act and thing which they, or any of them, may deem necessary or advisable
  to be done in connection with this registration statement, as fully to all
  intents and purposes as he or she might or could do in person, hereby ratifying
  and confirming all that said attorneys-in-fact and agents or any of them, or any
  substitute or substitutes for him or her, or any or all of them, may lawfully do
  or cause to be done by virtue hereof.
  
       Pursuant to the requirements of the Securities Act, this registration
  statement has been signed by the following persons in the indicated capacities
  as of June 13, 2001.
  
            SIGNATURE                     TITLE
            ---------                     -----
  
  /s/ Franklin M. Fisher          Chairman of the Board
  ----------------------------
  Franklin M. Fisher
  
  /s/ James C. Burrows            President, Chief Executive Officer and Director
  ----------------------------   (Principal Executive Officer)
  James C. Burrows
  
  /s/ Marybeth Celorier           Vice President and Treasurer
  ----------------------------   (Principal Financial and Accounting Officer)
  Marybeth Celorier
  5
  /s/ William F. Concannon        Director
  ----------------------------
  William F. Concannon
  
  /s/ Carl Kaysen                 Director
  ----------------------------
  Carl Kaysen
  
  /s/ Rowland T. Moriarty         Director
  ----------------------------
  Rowland T. Moriarty
  
  /s/ J. Robert S. Prichard       Director
  ----------------------------
  J. Robert S. Prichard
  
  /s/ Steven C. Salop             Director
  ----------------------------
  Steven C. Salop
  
  /s/ Carl B. Shapiro             Director
  ----------------------------
  Carl B. Shapiro
  6
                                   EXHIBIT INDEX
  
  EXHIBIT
  NUMBER      DESCRIPTION
  -------     -----------
  
     5.1      Opinion of Foley, Hoag & Eliot LLP.
    23.1      Consent of Ernst & Young LLP, independent auditors.
    23.2      Consent of Foley, Hoag & Eliot LLP (included in Exhibit 5.1).
    24.1      Power of attorney (contained on the signature page of this
              registration statement).