<Page>
- -------------------------------------------------------------------------------
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
----------------------
FORM 8-K
----------------------
CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(d) OF THE
SECURITIES EXCHANGE ACT OF 1934
DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED): DECEMBER 6, 2002
UNITED INDUSTRIES CORPORATION
-----------------------------
(EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
DELAWARE
--------
(STATE OR OTHER JURISDICTION OF INCORPORATION OR ORGANIZATION)
333-76055 43-1025604
--------- ----------
(COMMISSION FILE NUMBER) (I.R.S. EMPLOYER
IDENTIFICATION NUMBER)
8825 PAGE BOULEVARD
ST. LOUIS, MISSOURI 63114
-------------------------
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES INCLUDING ZIP CODE)
(314) 427-0780
--------------
(REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE)
NOT APPLICABLE
--------------
(FORMER NAME OR FORMER ADDRESS, IF CHANGED SINCE LAST REPORT)
- -------------------------------------------------------------------------------
<Page>
ITEM 5. OTHER EVENTS.
On December 6, 2002, United Industries Corporation (the Company), conducting
business as Spectrum Brands, announced its acquisition of WPC Brands, Inc. The
acquisition resulted in the addition of certain complementary products to the
Company's portfolio of brands, including the Repel(R) insect repellant brand.
A copy of the press release is being filed as Exhibit 99.1 with this report.
- ------------------------------------------------------------------------------=
<Page>
ITEM 7. EXHIBITS.
<Table>
<Caption>
EXHIBIT
NUMBER EXHIBIT DESCRIPTION
- ------- -------------------
99.1 Press release dated December 6, 2002.
</Table>
- -------------------------------------------------------------------------------
<Page>
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, United
Industries Corporation has duly caused this Current Report to be signed on its
behalf by the undersigned hereunto duly authorized.
UNITED INDUSTRIES CORPORATION,
------------------------------
Registrant
Dated: December 9, 2002
By: /s/ Daniel J. Johnston
---------------------------------
Name: Daniel J. Johnston
Title: EXECUTIVE VICE PRESIDENT AND
CHIEF FINANCIAL OFFICER (PRINCIPAL
FINANCIAL AND ACCOUNTING OFFICER)
- -------------------------------------------------------------------------------
<Page>
EXHIBIT INDEX
<Table>
<Caption>
EXHIBIT
NUMBER EXHIBIT DESCRIPTION
- ------- --------------------
99.1 Press release dated December 6, 2002.
</Table>