SIXTH SUPPLEMENT DATED APRIL 3, 1998
TO FIFTH SUPPLEMENT DATED APRIL 1, 1998,
FOURTH SUPPLEMENT DATED MARCH 23, 1998,
THIRD SUPPLEMENT DATED FEBRUARY 25, 1998,
SECOND SUPPLEMENT DATED JANUARY 21, 1998,
PROSPECTUS SUPPLEMENT DATED DECEMBER 19, 1997,
AND PROSPECTUS DATED NOVEMBER 26, 1997
COSTCO COMPANIES, INC.
The following table sets forth certain information as of April 3, 1998,
as to the security ownership of a person not named as a Selling Securityholder
in the Prospectus dated November 26, 1997 ("Prospectus") or the Prospectus
Supplements dated December 19, 1997, or January 21, February 25, March 23 or
April 1, 1998.
<TABLE>
<CAPTION>
Face Amount of Notes Owned Shares of Common Stock
Prior to Offering Owned Prior
Selling Securityholder to Offering (1)
- ----------------------
<S> <C> <C>
BZW Securities Limited $50,000,000 567,725
- ---------------------------------------
(1) Includes the Shares into which the Notes are convertible.
</TABLE>
The date of this Prospectus Supplement is
April 3, 1998.
