<PAGE>
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549

                                   FORM 10-K/A
                                 AMENDMENT NO. 2

                                  ANNUAL REPORT
                       PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2002         Commission file number 1-496

                              HERCULES INCORPORATED

                             A DELAWARE CORPORATION
                  I.R.S. EMPLOYER IDENTIFICATION NO. 51-0023450
                                 HERCULES PLAZA
                            1313 NORTH MARKET STREET
                         WILMINGTON, DELAWARE 19894-0001
                             TELEPHONE: 302-594-5000


           Securities registered pursuant to Section 12(b) of the Act
        (Each class is registered on the New York Stock Exchange, Inc.)

                               Title of each class
                               -------------------
                       Common Stock ($25/48 Stated Value)
           8% Convertible Subordinated Debentures due August 15, 2010
     9.42% Trust Originated Preferred Securities ($25 liquidation amount),
                           issued by Hercules Trust I
                     and guaranteed by Hercules Incorporated
                        Preferred Share Purchase Rights

      Indicate by check mark whether the Registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days. Yes X No _

      Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of Registrant's knowledge, in definitive proxy or information statements in
Part III of this Form 10-K/A or any amendment to this Form 10-K/A. _

      Indicate by check mark whether the Registrant is an accelerated filer (as
defined by Rule 12b-2 of the Act). Yes X No _

      The aggregate market value of registrant's common stock, $25/48 stated
value ("Common Stock") held by non-affiliates based on the closing price on the
last day of the Company's most recently completed second fiscal quarter, or June
28, 2002, was approximately $1.2 billion.

      As of March 31, 2003, registrant had 109,922,726 shares of Common Stock
outstanding, which is registrant's only class of common stock.

      On the corporate website, www.herc.com, Hercules Incorporated provides
access to the Company's filings with the Securities and Exchange Commission via
a hyperlink to the Commission's website.
<PAGE>
HERCULES INCORPORATED

EXPLANATORY NOTE

     Due to processing problems, the amendment to the Form 10-K filed by the
Company on April 30, 2003 listed, but did not actually include, newly filed
exhibits. This amendment to the Form 10-K is being filed solely to file those
exhibits.

                                     PART IV

ITEM 15.  EXHIBITS, FINANCIAL STATEMENT SCHEDULES AND REPORTS ON FORM 8-K

      (a) Documents filed as part of this Report:

            3. Exhibits:

                  A complete listing of exhibits is included in the Exhibit
                  Index that precedes the exhibits filed with this Report.


                                       2
<PAGE>
HERCULES INCORPORATED

                                   SIGNATURES

      Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed on
its behalf by the undersigned, thereunto duly authorized.

                                        HERCULES INCORPORATED

                   By:                  /s/ Fred G. Aanonsen
                                        ----------------------------------------
                                        Fred G. Aanonsen
                                        Vice President and Controller
                                        (Principal Financial Officer and duly
                                        authorized signatory)
                                        May 1, 2003


                                       3
<PAGE>
HERCULES INCORPORATED

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, William H. Joyce, Chairman and Chief Executive Officer, certify that:


1.    I have reviewed this annual report on Form 10-K/A of Hercules
      Incorporated;

2.    Based on my knowledge, this annual report does not contain any untrue
      statement of a material fact or omit to state a material fact necessary to
      make the statements made, in light of the circumstances under which such
      statements were made, not misleading with respect to the period covered by
      this annual report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this annual report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the registrant as of, and for, the periods presented in this annual
      report;

4.    The registrant's other certifying officers and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
      have:

      a)    designed such disclosure controls and procedures to ensure that
            material information relating to the registrant, including its
            consolidated subsidiaries, is made known to us by others within
            those entities, particularly during the period in which this annual
            report is being prepared;

      b)    evaluated the effectiveness of the registrant's disclosure controls
            and procedures as of a date within 90 days prior to the filing date
            of this annual report (the "Evaluation Date"); and

      c)    presented in this annual report our conclusions about the
            effectiveness of the disclosure controls and procedures based on our
            evaluation as of the Evaluation Date;

5.    The registrant's other certifying officers and I have disclosed, based on
      our most recent evaluation, to the registrant's auditors and the audit
      committee of registrant's board of directors (or persons performing the
      equivalent functions):

      a)    all significant deficiencies in the design or operation of internal
            controls which could adversely affect the registrant's ability to
            record, process, summarize and report financial data and have
            identified for the registrant's auditors any material weaknesses in
            internal controls; and

      b)    any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal controls; and


6.    The registrant's other certifying officers and I have indicated in this
      annual report whether there were significant changes in internal controls
      or in other factors that could significantly affect internal controls
      subsequent to the date of our most recent evaluation, including any
      corrective actions with regard to significant deficiencies and material
      weaknesses.

Date: May 1, 2003




/s/ William H. Joyce
------------------------------------
William H. Joyce
Chairman and Chief Executive Officer


                                       4
<PAGE>
HERCULES INCORPORATED

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Fred G. Aanonsen, Vice President and Controller, certify that:


1.    I have reviewed this annual report on Form 10-K/A of Hercules
      Incorporated;

2.    Based on my knowledge, this annual report does not contain any untrue
      statement of a material fact or omit to state a material fact necessary to
      make the statements made, in light of the circumstances under which such
      statements were made, not misleading with respect to the period covered by
      this annual report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this annual report, fairly present in all material
      respects the financial condition, results of operations and cash flows of
      the registrant as of, and for, the periods presented in this annual
      report;

4.    The registrant's other certifying officers and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
      have:

      a)    designed such disclosure controls and procedures to ensure that
            material information relating to the registrant, including its
            consolidated subsidiaries, is made known to us by others within
            those entities, particularly during the period in which this annual
            report is being prepared;

      b)    evaluated the effectiveness of the registrant's disclosure controls
            and procedures as of a date within 90 days prior to the filing date
            of this annual report (the "Evaluation Date"); and

      c)    presented in this annual report our conclusions about the
            effectiveness of the disclosure controls and procedures based on our
            evaluation as of the Evaluation Date;

5.    The registrant's other certifying officers and I have disclosed, based on
      our most recent evaluation, to the registrant's auditors and the audit
      committee of registrant's board of directors (or persons performing the
      equivalent functions):

      a)    all significant deficiencies in the design or operation of internal
            controls which could adversely affect the registrant's ability to
            record, process, summarize and report financial data and have
            identified for the registrant's auditors any material weaknesses in
            internal controls; and

      b)    any fraud, whether or not material, that involves management or
            other employees who have a significant role in the registrant's
            internal controls; and

6.    The registrant's other certifying officers and I have indicated in this
      annual report whether there were significant changes in internal controls
      or in other factors that could significantly affect internal controls
      subsequent to the date of our most recent evaluation, including any
      corrective actions with regard to significant deficiencies and material
      weaknesses.

Date: May 1, 2003




/s/ Fred G. Aanonsen
-----------------------------
Fred G. Aanonsen
Vice President and Controller


                                       5
<PAGE>
HERCULES INCORPORATED

EXHIBIT INDEX

<TABLE>
<CAPTION>
NUMBER                                DESCRIPTION                                      INCORPORATED BY REFERENCE TO
------                                -----------                                      ----------------------------
<S>             <C>                                                          <C>
2-A             Agreement and Plan of Merger among Hercules, Water           Exhibit 2.1, BetzDearborn Inc. Current Report
                Acquisition Company and BetzDearborn Inc., dated             on Form 8-K, filed July 30, 1998
                July 30, 1998

3-A.1           Restated Certificate of Incorporation of Hercules, as        Exhibit 3-A, Annual Report on Form 10-K filed
                revised and amended July 6, 1988                             March 26, 1993

3-A.2           Certificate of Amendment dated October 24, 1995, to          Exhibit 4.1a, Registration Statement on Form S-3,
                Hercules' Restated Certificate of Incorporation as           filed September 15, 1998
                revised and amended July 5, 1998

3-B             By-Laws of Hercules, as revised and amended October 30,      Exhibit 3-B, Annual Report on Form 10-K filed
                1991                                                         March 26, 1993

4-A             Officers' Certificate, dated as of March 17, 1999,           Exhibit 4.1, Current Report on Form 8-K dated
                pursuant to the Junior Subordinated Debentures               March 17, 1999
                Indenture between Hercules and Chase

4-B             Form of Preferred Securities Guarantee by Hercules and       Exhibit 4.28, Amendment No. 1 to Registration
                Chase, with respect to Hercules Trust I                      Statement on Form S-3, filed October 29, 1998

4-C             Form of Amended and Restated Trust Agreement of              Exhibit 4.13, Amendment No. 1 to Registration
                Hercules Trust I                                             Statement on Form S-3, filed October 29, 1998

4-D             Form of 9.42% Trust Originated Preferred Securities of       Exhibit 4.2, Current Report on Form 8-K, dated
                Hercules Trust I                                             March 17, 1999

4-E             Form of 9.42% Junior Subordinated Deferrable Interest        Exhibit 4.3, Current Report on Form 8-K, dated
                Debentures due 2029                                          March 17, 1999

4-F             Officers' Certificate, dated as of July 27, 1999,            Exhibit 4.1, Current Report on Form 8-K, dated
                pursuant to the Junior Subordinated Debentures               July 27, 1999
                Indenture between Hercules and Chase, dated as of
                November 12, 1998

4-G             Amended and Restated Trust Agreement of Hercules Trust       Exhibit 4.2, Current Report on Form 8-K, dated
                II, dated as of July 27, 1999, together with Annex I         July 27, 1999
                thereto

4-H             Unit Agreement, dated July 27, 1999, among Hercules,         Exhibit 4.3, Current Report on Form 8-K, dated
                Hercules Trust II and The Chase Manhattan Bank, as unit      July 27, 1999
                agent

4-I             Warrant Agreement, dated July 27, 1999, between              Exhibit 4.4, Current Report on Form 8-K, dated
                Hercules and The Chase Manhattan Bank, as warrant            July 27, 1999
                agent

4-J             Form of Series A Junior Subordinated Deferrable              Exhibit 4.5, Current Report on Form 8-K, dated
                Interest Debentures                                          July 27, 1999

4-K             Form of Trust II Preferred Securities                        Exhibit 4.6, Current Report on Form 8-K, dated
                                                                             July 27, 1999

4-L             Form of CRESTS Unit                                          Exhibit 4.7, Current Report on Form 8-K, dated
                                                                             July 27, 1999

4-M             Form of Warrant                                              Exhibit 4.8, Current Report on Form 8-K, dated
                                                                             July 27, 1999

4-N             Rights Agreement, dated as of August 24, 2000, between       Exhibit 4.1 to Hercules Registration of
                Hercules Incorporated and Chase Mellon Shareholder           Certain Classes of Securities on Form 8-A
                Services, L.L.C.                                             filed August 10, 2000
</TABLE>


                                       6
<PAGE>
HERCULES INCORPORATED

<TABLE>
<CAPTION>
NUMBER                                DESCRIPTION                                      INCORPORATED BY REFERENCE TO
------                                -----------                                      ----------------------------
<S>             <C>                                                          <C>
4-O             Indenture, dated as of November 14, 2000, between            Exhibit 4-A, Quarterly Report on Form 10-Q,
                Hercules Incorporated, as issuer and Wells Fargo Bank        filed November 14, 2000
                Minnesota, N.A., as trustee (including the form of
                11 1/8% senior notes due 2007 included as Exhibit A
                thereto).

4-P             Registration Rights Agreement, dated as of November 14,      Exhibit 4-B Quarterly Report on Form 10-Q,
                2000, among Hercules Incorporated and all of its             filed November 14, 2000
                domestic subsidiaries and Donaldson, Lufkin & Jenrette
                Securities Corporation and Credit Suisse First Boston
                Corporation, as the initial purchasers.
</TABLE>

Hercules is party to several long-term debt instruments under which in each case
the total amount of securities authorized does not exceed 10% of the total
assets of Hercules. Hercules agrees to furnish a copy of such instruments to the
Securities and Exchange Commission upon request.

<TABLE>
<S>             <C>                                                          <C>
10-A            Hercules Executive Survivor Benefit Plan                     Exhibit 10-D, Annual Report on Form 10-K,
                                                                             filed March 27, 1981

10-B            Hercules Phantom Stock Plan                                  Exhibit E, Notice Annual Meeting and Proxy
                                                                             Statement, dated February 14, 1986

10-C            Hercules Deferred Compensation Plan                          Exhibit 10-I, Annual Report on Form 10-K,
                                                                             filed March 29, 1988

10-D            Hercules Annual Management Incentive Compensation Plan       Exhibit 10-H, Annual Report on Form 10-K,
                                                                             filed March 26, 1993

10-E            Hercules 1993 Non-employee Director Stock Accumulation       Exhibit 4.1, Registration Statement on Form
                Plan                                                         S-8, filed July 16, 1993

10-F            Hercules Deferred Compensation Plan for Non-employee         Exhibit 10-J, Annual Report on Form 10-K,
                Directors                                                    filed March 26, 1993

10-G            Hercules Employee Pension Restoration Plan                   Exhibit 10-L, Annual Report on Form 10-K,
                                                                             filed March 26, 1993

10-H            Form of Employment Contract between Hercules and             Exhibit 10-J, Annual Report on Form 10-K,
                certain of its officers                                      filed March 29, 1988

10-I            Form of Indemnification Agreement between Hercules           Annex II, Notice of Annual Meeting and Proxy
                and certain officers and directors of Hercules               Statement, dated February 19, 1987

10-J            Employment Agreement effective August 1, 1998, between       Exhibit 10-T, Annual Report on Form 10-K,
                Hercules and Vincent J. Corbo                                filed March 30, 1999

10-K            Hercules Amended and Restated Long Term Incentive            Exhibit 10-K, Annual Report on Form 10-K,
                Compensation Plan                                            filed March 29, 2000

10-L            BetzDearborn Inc. Employee Stock Ownership and 401(k)        Exhibit 10-L, Annual Report on Form 10-K,
                Plan                                                         filed March 29, 2000

10-M            Underwriting Agreement, dated March 12, 1999, among          Exhibit 1.1, Current Report on Form 8-K, dated
                Hercules, Hercules Trust I and the Underwriters named        March 17, 1999
                therein

10-N            CRESTS Units Underwriting Agreement, dated July 21,          Exhibit 1.1, Current Report on Form 8-K, dated
                1999, among Hercules, Hercules Trust II and the              July 27, 1999
                Underwriters named therein

10-O            Common Stock Underwriting Agreement, dated July              Exhibit 1.2, Current Report on Form 8-K, dated
                21, 1999, among Hercules and the Underwriters                July 27, 1999
                named therein
</TABLE>


                                       7
<PAGE>
HERCULES INCORPORATED

<TABLE>
<CAPTION>
NUMBER                                DESCRIPTION                                      INCORPORATED BY REFERENCE TO
------                                -----------                                      ----------------------------
<S>             <C>                                                          <C>
10-P            Share Purchase Agreement, dated as of August 10, 2000,       Exhibit 2-1, Current Report on Form 8-K, dated
                among CP Kelco ApS (formerly known as Hercules               September 28, 2000
                Copenhagen ApS), Hercules Investment ApS, Hercules
                Incorporated, Lehman FG Newco, Inc., WSP, Inc. and
                Hercules Holding BV/BVBA

10-Q            Form of Change-of-Control Employment Agreements entered      Exhibit 10-19, Registration Statement on Form
                into as of August 24, 2002 by Hercules Incorporated and      S-4, filed August 9, 2001
                each of Robert C. Flexon and Craig A. Rogerson.

10-R            Resignation Agreement, dated as of October 17, 2000,         Exhibit 10-20, Registration Statement on Form
                between Hercules Incorporated and Vincent J. Corbo           S-4, filed August 9, 2001

10-S            Letter Agreement, dated November 1, 2000, between            Exhibit 10-21, Registration Statement on Form
                Hercules Incorporated and Harry J. Tucci                     S-4, filed August 9, 2001

10-T            Letter Agreement, dated November 1, 2000, between            Exhibit 10-B, Quarterly Report on Form 10-Q,
                Hercules Incorporated and Thomas L. Gossage                  filed May 16, 2001

10-U            Employment Agreement, effective as of May 8, 2001,           Exhibit 10-A, Quarterly Report on Form 10-Q,
                between Hercules Incorporated and William H. Joyce           filed May 16, 2001

10-V            Change-of-Control Employment Agreement, dated as of May      Exhibit 10-24, Registration Statement on Form
                8, 2001, by and between Hercules Incorporated and            S-4, filed August 9, 2001
                William H. Joyce

10-W            Form of Change-of-Control Employment Agreement entered       Exhibit 10-25, Registration Statement on Form
                into as of June 15, 2001 by Hercules Incorporated and        S-4, filed August 9, 2001
                Richard G. Dahlen

10-X            Separation Agreement and General Release of Claims,          Exhibit 10-26, Registration Statement on Form
                dated June 22, 2001, between Hercules Incorporated and       S-4, filed August 9, 2001
                June B. Barry

10-Y            Separation Agreement and General Release of                  Exhibit 10-27, Registration Statement on Form S-4,
                Claims, dated June 21, 2001, between Hercules                filed August 9, 2001
                Incorporated and George MacKenzie

10-Z            Change-of-Control Employment Agreement, dated as of          Exhibit 10-28, Registration Statement on Form
                July 2, 2001, by and between Hercules Incorporated and       S-4, filed August 9, 2001
                Fred G. Aanonsen

10-Aa           Stock and Asset Purchase Agreement, dated as of              Exhibit 10.1, Current Report on Form 8-K, dated
                February 12, 2002, by and among Hercules                     February 12, 2002
                Incorporated, General Electric Company and Falcon
                Acquisition Corp.

10-Bb           Amendment 2002-1 to Amended and Restated Long Term           Exhibit I, Notice of Annual Meeting and Proxy
                Incentive Compensation Plan                                  Statement, dated May 15, 2002

10-Cc           Amendment 2002-1 to Non-Employee Director Stock              Exhibit II, Notice of Annual Meeting and Proxy
                Accumulation Plan                                            Statement, dated May 15, 2002

10-Dd           Credit Agreement, dated December 20, 2002, among             Exhibit 10-Dd, Annual Report on Form 10-K,
                Hercules Incorporated, certain subsidiaries of               filed March 31, 2003
                Hercules, several banks and other financial
                institutions identified in the agreement and Credit
                Suisse First Boston, as administrative agent

10-Ee*          Hercules Incorporated Compensation Benefits Grantor
                Trust Agreement for Management Employees
</TABLE>


                                       8
<PAGE>
HERCULES INCORPORATED

<TABLE>
<CAPTION>
NUMBER                                DESCRIPTION                                      INCORPORATED BY REFERENCE TO
------                                -----------                                      ----------------------------
<S>             <C>                                                          <C>
10-Ff*          Hercules Incorporated Compensation Benefits Grantor
                Trust Agreement for Nonemployee Directors

10-Gg*          Amended and Restated Hercules Incorporated Management
                Incentive Compensation Plan, dated February 21, 2003

21.1            Subsidiaries of Registrant                                   See Part II, Item 8 on page 79 of Annual
                                                                             Report on Form 10-K, filed March 31, 2003

23.1            Consent of Independent Accountants                           Exhibit 23.1, Annual Report on Form 10-K,
                                                                             filed March 31, 2003

99.1            Certification of Chairman and Chief Executive Officer        Exhibit 99.1, Annual Report on Form 10-K,
                Pursuant to 18. U.S.C. Section 1350, as adopted              filed March 31, 2003
                pursuant to Section 906 of the Sarbanes-Oxley Act of
                2002

99.2            Certification of Vice President and Controller Pursuant      Exhibit 99.2, Annual Report on Form 10-K,
                to 18. U.S.C. Section 1350, as adopted pursuant to           filed March 31, 2003
                Section 906 of the Sarbanes-Oxley Act of 2002

99.3            Certification of Chairman and Chief Executive Officer        Exhibit 99.3, Annual Report on Form 10-K/A,
                Pursuant to 18. U.S.C. Section 1350, as adopted              filed April 30, 2003
                pursuant to Section 906 of the Sarbanes-Oxley Act of
                2002

99.4            Certification of Vice President and Controller Pursuant      Exhibit 99.4, Annual Report on Form 10-K/A,
                to 18. U.S.C. Section 1350, as adopted pursuant to           filed April 30, 2003
                Section 906 of the Sarbanes-Oxley Act of 2002

99.5*           Certification of Vice President and Controller Pursuant
                to 18. U.S.C. Section 1350, as adopted pursuant to
                Section 906 of the Sarbanes-Oxley Act of 2002

99.6*           Certification of Chairman and Chief Executive Officer
                Pursuant to 18. U.S.C. Section 1350, as adopted
                pursuant to Section 906 of the Sarbanes-Oxley Act of
                2002
</TABLE>

*  Filed herewith


                                       9