SUPPLEMENT DATED DECEMBER 19, 1997
TO PROSPECTUS DATED NOVEMBER 26, 1997
COSTCO COMPANIES, INC.
The following table sets forth certain information as of December 19, 1997,
as to the security ownership of persons not named as Selling Securityholders in
the Prospectus dated November 26, 1997, and information reflecting additional
securities acquired by Donaldson Lufkin & Jenrette Securities Corp. ("DLJ")
since it was named as a Selling Shareholder in the Prospectus. Amounts shown for
DLJ are not adjusted for any sales that DLJ may have made pursuant to the
Registration Statement of which the Prospectus and this Prospectus Supplement
form a part. DLJ has provided and will continue to provide financial advisory
services to Costco Companies, Inc. (the "Company") for which DLJ has received
customary fees. Hamilton E. James, a Managing Director of DLJ, is a member of
the Board of Directors of the Company. Except as set forth for DLJ, none of the
Selling Securityholders listed below has had a material relationship with the
Company or any of its predecessors or affiliates within the past three years.
<TABLE>
<CAPTION>
Shares of
Face Amount of Common Stock
Notes Owned Owned Prior
Selling Securityholder Prior to Offering to Offering(1)
<S> <C> <C>
Argent Classic Convertible Arbitrage Fund $22,500,000 255,476
(Bermuda) L.P.
Baptist Health 513,000 5,824
Black Diamond Ltd. 3,297,000 37,435
Black Diamond Partners, L.P. 3,524,000 40,013
Boston Museum of Fine Arts 218,000 2,475
BT Holdings (New York) Inc. 6,500,000 73,804
Donaldson, Lufkin & Jenrette Securities 73,770,000 (2) 837,621 (2)
Corporation
Dunham & Associates Fund III 62,000 703
Dunham & Associates Fund II 139,000 1,578
Engineers Joint Pension Fund 803,000 9,117
Highbridge Capital Corp. 323,000 3,667
Natwest Securities 2,000,000 22,709
New York Life Insurance Company 30,000,000 340,635
Nicholas-Applegate Global Growth & Income 160,000 1,816
Fund
Nicholas-Applegate Income & Growth Fund 6,678,000 75,825
Northwestern Mutual Life Insurance Company 5,000,000 (3) 130,830 (4)
Rich Yakomin 10,000,000 113,545
San Diego City Retirement 1,597,000 18,133
San Diego County Convertible 6,749,000 76,631
Silverton International Fund Limited 2,000,000 22,709
Strategic Money Management Company, B.V. 3,000,000 34,063
TCW Group, Inc. 27,045,000 307,082
Tribeca Investments, L.L.C. 17,990,000 204,267
Wake Forest University 1,247,000 14,159
Worldwide Transactions Limited 356,000 4,042
(1) Includes the Shares into which the Notes are convertible.
(2) Includes securities previously registered.
(3) Includes $1,000,000 in principal amount held in The Northwestern Mutual
Life Insurance Company Group Annuity Separate Account.
(4) As the parent of Northwestern Mutual Series Fund, Inc. and affiliate of
Mason Street Funds, Inc., the Selling Securityholder is the indirect beneficial
owner with shared investment and shared voting power over an additional 74,058
shares of Common Stock.
</TABLE>
The date of this Prospectus Supplement is December 19, 1997.
