<PAGE>
FILED PURSUANT TO RULE 424(b)(3)
FILE NO. 333-45295
SUPPLEMENT TO
PROSPECTUS DATED AUGUST 5, 1998
ECOLAB INC.
555,018 SHARES OF COMMON STOCK
This document supplements the Prospectus, dated August 5, 1998, relating to
the proposed sale of up to 555,018 shares of common stock (including the
preferred stock purchase rights attached to those shares).
On October 13, 1998, Sherman Gleekel, who was identified in the Prospectus
as beneficially owning 250,514 of the offered shares, transferred 23,760 of
those shares to his children and trusts created for the benefit of his
grandchildren. The name of each transferee and the number of shares transferred
is indicated below.
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<CAPTION>
Shares
Transferee Transferred
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<S> <C>
Peter Gleekel 7,000
Mack Gleekel 7,000
Anthony Gleekel 7,000
Cade Daniel Gleekel Trust
u/a dated July 22, 1998(1) 690
Benjamin Brozic Gleekel Trust
u/a dated July 22, 1998(1) 690
Isabel Brozic Gleekel Trust
u/a dated July 22, 1998(1) 690
Joseph Ross Gleekel Trust
u/a dated July 22, 1998(1) 690
</TABLE>
(1) Peter, Mack and Anthony Gleekel are the Trustees of these trusts.
Each of these transferees will be a "Selling Stockholder" under the
Prospectus and the shares transferred to them will be covered by the Prospectus.
The table on page 5 of the Prospectus is amended to add the information provided
above.
THE DATE OF THIS PROSPECTUS SUPPLEMENT IS OCTOBER 20, 1998
