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

                                   FORM 10-K/A

(MARK ONE)

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

                      FOR THE FISCAL YEAR ENDED DECEMBER 31, 2002

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

                         COMMISSION FILE NUMBER: 1-15157

                               PACTIV CORPORATION
             (Exact name of Registrant as Specified in its Charter)

                     DELAWARE                                 36-2552989
          (State or other jurisdiction of                  (I.R.S. Employer
          incorporation or organization)                  Identification No.)

               1900 WEST FIELD COURT
               LAKE FOREST, ILLINOIS                             60045
      (Address of principal executive offices)                (Zip Code)

       Registrant's telephone number, including area code: (847) 482-2000

SECURITIES REGISTERED PURSUANT TO SECTION 12 (b) OF THE ACT:


                                                          NAME OF EACH EXCHANGE
             TITLE OF EACH CLASS                           ON WHICH REGISTERED
----------------------------------------------          ------------------------
      Common Stock ($.01 par value) and                  New York Stock Exchange
  associated Preferred Stock Purchase Rights

     Securities registered pursuant to Section 12(g) of the Act: None

     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
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [X]

     Indicate by check mark whether the registrant is an accelerated filer (as
defined in Rule 12b-2 of the Act).

                                                  Yes [X] No [ ]

         State the aggregate market value of the voting stock held by
non-affiliates of the registrant. The aggregate market value is computed by
reference to the price at which the stock was sold, or the average bid and asked
prices of such stock, as of the last business day of the registrant's most
recently completed second fiscal quarter.

CLASS OF VOTING STOCK AND NUMBER OF SHARES          MARKET VALUE OF COMMON STOCK
  HELD BY NON-AFFILIATES AT JUNE 28, 2002              HELD BY NON-AFFILIATES
------------------------------------------          ----------------------------
     COMMON STOCK 157,485,313 SHARES                       $3,748,150,447

     INDICATE THE NUMBER OF SHARES OUTSTANDING OF EACH OF THE REGISTRANT'S
CLASSES OF COMMON STOCK, AS OF THE LATEST PRACTICABLE DATE. Common Stock ($.01
par value). 159,147,846 shares outstanding as of February 28, 2003.
(See Note 12 to the Financial Statements.)

DOCUMENTS INCORPORATED BY REFERENCE:

                                                        PART OF THE FORM 10-K
                   DOCUMENT                             INTO WHICH INCORPORATED
                   --------                             -----------------------
Pactiv Corporation's Definitive Proxy Statement              Part III
for the Annual Meeting of Shareholders to be
held May 16, 2003

<PAGE>
                                EXPLANATORY NOTE

         This amendment to Pactiv Corporation's Annual Report on Form 10-K for
the fiscal year ended December 31, 2002, is being filed to correct a
typographical error in the tabular presentation of the company's
equity-compensation plans contained in Item 12. The total number of shares of
common stock issuable under plans shown in the left column of the table
appearing in Item 12 (page 53) has been revised to 15,341,967. No revisions have
been made to the Pactiv Corporation financial statements or any other
disclosures contained in the Annual Report.


ITEM 12. SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND
RELATED STOCKHOLDER MATTERS


     The following table summarizes the company's equity-compensation plans at
December 31, 2002.

<Table>
<Caption>
                                                                                         Number of shares
                                                                                         of common stock
                                      Number of shares of        Weighted-average           remaining
                                      common stock to be             exercise             available for
                                          issued upon                price of            future issuance
                                          exercise of              outstanding             under equity
        Plan category                 outstanding options            options            compensation plans
-------------------------------      ---------------------       ---------------       --------------------
<S>                                  <C>                         <C>                   <C>
Equity-compensation plans
approved by shareholders                  14,803,965(1)             $21.19                 12,106,292

Equity-compensation plans not
approved by shareholders                     538,002(2)             $14.97(3)               2,686,747(4)
                                          ----------                ------                 ----------
Total                                     15,341,967                $21.15                 14,793,039
                                          ----------                ------                 ----------
</Table>


(1)  Includes outstanding options and performance share awards. The outstanding
     performance share awards are subject to vesting based on future performance
     criteria and/or continued employment, and all such awards may be paid in
     stock or in cash, at the discretion of the Compensation Committee.

(2)  Includes shares purchased, or available for purchase, by employees pursuant
     to the Pactiv Corporation Employee Stock Purchase Plan, which allows U.S.
     and Canadian employees to purchase Pactiv common stock at a 15% discount,
     subject to an annual limitation of $21,240. See Note 12 to the financial
     statements for additional information regarding the Employee Stock Purchase
     Plan. As of December 31, 2002, there were pending purchases for 92,611
     shares (shares that employees had elected to purchase and paid the purchase
     price), which were issued in early January 2003. Also includes units
     (Common Stock Equivalents) invested in the Pactiv Common Stock Index under
     the Pactiv Corporation Deferred Compensation Plan. Under the Deferred
     Compensation Plan, directors and officers may defer receipt of all or a
     portion of their retainer, bonus or other incentive compensation, in which
     event such deferred amounts will be "indexed" against the investment
     options selected by the participant. One of the investment options is the
     Pactiv Common Stock Index. If a participant has selected the Pactiv Common
     Stock Index, at the end of the deferral period (ordinarily upon termination
     of employment or service as a director), the participant may receive cash
     or Pactiv common stock. As of December 31. 2002, there were 445,391 units
     of Common Stock Equivalents held in the Pactiv Common Stock Index Fund
     under the Deferred Compensation Plan.

(3)  Represents the purchase price for the pending purchase (as of December 31,
     2002) of 92,611 shares purchased under the Employee Stock Purchase Plan. No
     amount is included in this calculation with respect to the units held under
     the Deferred Compensation Plan.

(4)  Represents shares reserved for issuance under the Employee Stock Purchase
     Plan as of December 31, 2002, less shares for which as of such date
     employees had elected to purchase and paid for (through payroll deductions)
     but which had not yet been issued.

<PAGE>
                                  SIGNATURES

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

                                              PACTIV CORPORATION

                                              By:
                                                 /s/ RICHARD L. WAMBOLD
                                                 -------------------------------
                                                 Richard L. Wambold
                                                 Chairman, President and
                                                 Chief Executive Officer
Date: March 28, 2003

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following on behalf of the registrant and in
the capacities and on the dates indicated.


<TABLE>
<CAPTION>
                  SIGNATURE                                            TITLE                           DATE
                  ---------                                            -----                           ----
<S>                                                      <C>                                         <C>
/s/       RICHARD L. WAMBOLD                             Chairman, President, Chief Executive        March 28, 2003
---------------------------------------------            Officer and Director (principal
          Richard L. Wambold                             executive officer)



/s/       ANDREW A. CAMPBELL                             Senior Vice President and Chief             March 28, 2003
---------------------------------------------            Financial Officer (principal
          Andrew A. Campbell                             financial and accounting officer)



/s/       LARRY D. BRADY*                                Director                                    March 28, 2003
---------------------------------------------
          Larry D. Brady


                                                         Director
---------------------------------------------
          K. Dane Brooksher


/s/       ROBERT J. DARNALL*                             Director                                    March 28, 2003
---------------------------------------------
          Robert J. Darnall


/s/       MARY R. (NINA) HENDERSON*                      Director                                    March 28, 2003
---------------------------------------------
          Mary R. (Nina) Henderson


/s/       ROGER B. PORTER*                               Director                                    March 28, 2003
---------------------------------------------
          Roger B. Porter


/s/       PAUL T. STECKO*                                Director                                    March 28, 2003
---------------------------------------------
          Paul T. Stecko


/s/       NORMAN H. WESLEY*                              Director                                    March 28, 2003
---------------------------------------------
          Norman H. Wesley


*By: /s/ JAMES V. FAULKNER, JR.                                                                      March 28, 2003
     ----------------------------------------
          James V. Faulkner, Jr.
          Attorney-in-fact

</TABLE>

                                       2
<PAGE>
                                  CERTIFICATION

I, Richard L. Wambold, the principal executive officer of Pactiv Corporation
(the "company"), certify that:

1. I have reviewed this annual report on Form 10-K for the company, as amended
   by the Form 10-K/A filed on this date; and

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 in
   order 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.


Date:  March 28, 2003


/s/   RICHARD L. WAMBOLD
-------------------------------
Richard L. Wambold
Principal Executive Officer


                                       3
<PAGE>

                                  CERTIFICATION

I, Andrew A. Campbell, the principal financial officer of Pactiv Corporation
(the "company"), certify that:

1. I have reviewed this annual report on Form 10-K for the company, as amended
   by the Form 10-K/A filed on this date; and

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 in
   order 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.



Date:  March 28, 2003


/s/  ANDREW A. CAMPBELL
----------------------------------
Andrew A. Campbell
Principal Financial Officer




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