<PAGE>

           As filed with the Securities and Exchange Commission on April 5, 2001

                                                     Registration No. 333-______
================================================================================

                     U.S. SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             -----------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933

                             -----------------------

                                   ECOLAB INC.
             (Exact name of registrant as specified in its charter)



                  DELAWARE                               41-0231510
       (State or Other Jurisdiction of                 (I.R.S. Employer
       Incorporation or Organization)                Identification No.)

                ECOLAB CENTER
          270 NORTH WABASHA STREET
             ST. PAUL, MINNESOTA                            55102
  (Address of Principal Executive Offices)               (Zip Code)

                             -----------------------

                     ECOLAB INC. 2001 NON-EMPLOYEE DIRECTOR
                   STOCK OPTION AND DEFERRED COMPENSATION PLAN
                            (Full Title of the Plan)

                             -----------------------

                            KENNETH A. IVERSON, ESQ.
                          VICE PRESIDENT AND SECRETARY
                                   ECOLAB INC.
                                  ECOLAB CENTER
                            370 NORTH WABASHA STREET
                            ST. PAUL, MINNESOTA 55102
                                 (651) 293-2125
                      (Name, address and telephone number,
                   including area code, of agent for service)

                            -------------------------

        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
           IMMEDIATELY UPON THE FILING OF THIS REGISTRATION STATEMENT

                            ------------------------

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
====================================================================================================================
   TITLE OF SECURITIES        AMOUNT TO BE         PROPOSED MAXIMUM           PROPOSED MAXIMUM          AMOUNT OF
     TO BE REGISTERED       REGISTERED(1)(2)   OFFERING PRICE PER UNIT(3) AGGREGATE OFFERING PRICE  REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------
<S>                         <C>                <C>                        <C>                       <C>
Common stock, par value
$1.00 per share(4)               500,000                $41.00                 $20,500,000.00           $5,125.00
====================================================================================================================
</TABLE>

(1)  This registration statement is also deemed, pursuant to Instruction E to
     Form S-8, to relate to (a) 206,600 shares of the 250,000 shares that had
     been previously registered on Form S-8 (File No. 333-21167) in connection
     with the Ecolab Inc. 1997 Non-Employee Director Deferred Compensation Plan,
     with respect to which a fee of $1,152.35 has been previously paid, and (b)
     118,400 shares of the 400,000 shares that had been previously registered on
     Form S-8 (File No. 33-59431) in connection with the Ecolab Inc. 1995
     Non-Employee Director Stock Option Plan, with respect to which a fee of
     $473.35 has been previously paid.
<PAGE>

(2)  In addition, pursuant to Rule 416(a) under the Securities Act of 1933, as
     amended (the "Securities Act"), this Registration Statement also covers an
     indeterminate number of additional shares of common stock to be offered or
     sold as a result of the anti-dilution provisions of the employee benefit
     plan described in this Registration Statement.

(3)  Estimated solely for the purpose of calculating the registration fee in
     accordance with Rule 457(h)(1) and (c) under the Securities Act, based upon
     the average of the high and low sale prices of the registrant's common
     stock on April 3, 2001, as reported on the Consolidated Transaction
     Reporting System of The New York Stock Exchange.

(4) Each share of common stock includes one-half share of a preferred stock
    purchase right.

<PAGE>

                                EXPLANATORY NOTE

         On February 5, 1997, a total of 125,000 shares (250,000 shares after
adjusting for a January 15, 1998 2-for-1 split) of the common stock (with
preferred stock purchase rights) of Ecolab Inc. ("Ecolab") were registered with
the Securities and Exchange Commission ("SEC") by a Registration Statement on
Form S-8 (File No. 333-21167) in connection with the Ecolab Inc. 1997
Non-Employee Director Deferred Compensation Plan. On May 18, 1995, a total of
200,000 shares (400,000 shares after adjusting for Ecolab's January 15, 1998
2-for-1 stock split) of Ecolab's common stock (with preferred stock purchase
rights) were registered with the Securities and Exchange Commission by a
Registration Statement on Form S-8 (File No. 33-59431) in connection with the
Ecolab Inc. 1995 Non-Employee Director Stock Option Plan. On February 23, 2001,
the Board of Directors of Ecolab approved the Ecolab Inc. 2001 Non-Employee
Director Stock Option and Deferred Compensation Plan, which replaces the Ecolab
Inc. 1997 Non-Employee Director Deferred Compensation Plan and the Ecolab Inc.
1995 Non-Employee Director Stock Option Plan. As of April 5, 2001, 206,600
shares of Ecolab's common stock registered under the Ecolab Inc. 1997
Non-Employee Director Deferred Compensation Plan and 118,400 shares of Ecolab's
common stock registered under the Ecolab Inc. 1995 Non-Employee Director Stock
Option Plan had not been issued under these plans and were not subject to
currently outstanding stock options. Pursuant to Instruction E to Form S-8 and
the telephonic interpretation of the Securities and Exchange Commission
pertaining to "Form S-8" set forth in the Division of Corporation Finance's
Telephone Interpretation Manual of Publicly-Available Telephone Interpretations
(July 1997), as supplemented from time to time thereafter, these remaining and
unissued shares are carried forward and deemed covered by this Registration
Statement on Form S-8 in connection with the Ecolab Inc. 2001 Non-Employee
Director Stock Option and Deferred Compensation Plan.


                                       1

<PAGE>

                                     PART I

                              INFORMATION REQUIRED
                         IN THE SECTION 10(a) PROSPECTUS

         The documents containing the information specified in Part I of Form
S-8 have been or will be sent or given to participants as specified by Rule
428(b)(1) under the Securities Act.


                                       2

<PAGE>

                                     PART II

                              INFORMATION REQUIRED
                          IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following documents filed by Ecolab (File No. 1-9328) with the SEC
are incorporated by reference in this Registration Statement:

         (1)      Annual report on Form 10-K for the year ended December 31,
                  2000;

         (2)      Current reports on Form 8-K dated January 16, 2001 and January
                  24, 2001;

         (3)      All other reports filed by Ecolab pursuant to Section 13(a) or
                  15(d) of the Securities Exchange Act of 1934, as amended (the
                  "Exchange Act"), since December 31, 2000; and

         (4)      The descriptions of Ecolab's common stock, preferred stock and
                  preferred stock purchase rights contained in its registration
                  statements on Form 8-A, including any amendments or reports
                  filed for the purpose of updating these descriptions.

         All documents filed by Ecolab with the SEC pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act after the date of this Registration
Statement and prior to the filing of a post-effective amendment which indicates
that all securities offered pursuant to this Registration Statement have been
sold or that deregisters all securities then remaining unsold, will be deemed to
be incorporated by reference in this Registration Statement and to be a part of
this Registration Statement from the date of filing of these documents.

         The consolidated financial statements and related financial statement
schedule of Ecolab, which are included or incorporated by reference in Ecolab's
Annual Report on Form 10-K for the year ended December 31, 2000, and
incorporated by reference in this Registration Statement, have been audited by
PricewaterhouseCoopers LLP, independent accountants, for the periods indicated
in such firm's reports thereon. The consolidated financial statements and
financial statement schedule audited by PricewaterhouseCoopers LLP have been
incorporated herein by reference in reliance on such firm's reports given upon
their authority as experts in accounting and auditing. To the extent that
PricewaterhouseCoopers LLP examines and reports on the financial statements and
financial statement schedules of Ecolab issued at future dates, and consents to
the use of their reports thereon, such financial statements and financial
statement schedules will also be incorporated by reference in this Registration
Statement in reliance upon their reports and said authority.

         In addition, the combined financial statements and related financial
statement schedule of Henkel-Ecolab, which are included in Ecolab's Annual
Report on Form 10-K for the year ended December 31, 2000, and incorporated by
reference in this Registration Statement, have been audited by
PricewaterhouseCoopers Gesellschaft mit beschrankter Haftung
Wirtschaftsprufungsgesellschaft, independent accountants. The combined financial
statements and related financial statement schedule audited by
PricewaterhouseCoopers Gesellschaft mit beschrankter Haftung
Wirtschaftsprufungsgesellschaft have been incorporated herein by reference in
reliance on such firm's reports given upon their authority as experts in
accounting and auditing. To the extent that PricewaterhouseCoopers Gesellschaft
mit beschrankter Haftung Wirtschaftsprufungsgesellschaft examines and reports on
the financial statements and financial statement schedules of Henkel-Ecolab
issued at future dates, and consents to the use of their reports thereon, such
financial statements and


                                       3

<PAGE>

financial statement schedules will also be incorporated by reference in this
Registration Statement in reliance upon their reports and said authority.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable. Ecolab's common stock and preferred stock purchase
rights to be offered and sold pursuant to this registration statement are
registered under Section 12 of the Exchange Act.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Subsection (a) of Section 145 of the General Corporation Law of
Delaware empowers a corporation to indemnify any person who was or is a party or
is threatened to be made a party to any threatened, pending or completed action,
suit or proceeding, whether civil, criminal, administrative or investigative
(other than an action by or in the right of the corporation), by reason of the
fact that such person is or was a director, officer, employee or agent of the
corporation or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation or enterprise,
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred by such person in connection with
such action, suit or proceeding if such person acted in good faith and in a
manner such person reasonably believed to be in or not opposed to the best
interests of the corporation, and with respect to any criminal action or
proceeding, had no reasonable cause to believe such person's conduct was
unlawful.

         Subsection (b) of Section 145 empowers a corporation to indemnify any
person who was or is a party or threatened to be made a party to any threatened,
pending or completed action or suit by or in the right of the corporation to
procure a judgment in its favor by reason of the fact that such person acted in
any of the capacities set forth above, against expenses actually and reasonably
incurred by such person in connection with the defense or settlement of such
action or suit if such person acted under similar standards, except that no
indemnification may be made in respect of any claim, issue or matter as to which
such person shall have been adjudged to be liable to the corporation unless and
only to the extent that the Court of Chancery or the court in which the action
or suit was brought shall determine that, despite the adjudication of liability,
the person is fairly and reasonably entitled to indemnity for the expenses which
the court shall deem proper.

         Section 145 further provides that, to the extent a director or officer
of a corporation has been successful in the defense of any action, suit or
proceeding referred to in subsections (a) and (b) or in the defense of any
claim, issue or matter therein, the person shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred in connection
therewith; that indemnification provided for by Section 145 shall not be deemed
exclusive of any other rights to which the indemnified party may be entitled;
and that the scope of indemnification extends to directors, officers, employees
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the constituent corporation
for another. Section 145 also empowers the corporation to purchase and maintain
insurance on behalf of a director or officer of the corporation against any
liability asserted against or incurred by the person in any such capacity or
arising out of the person's status as such, whether or not the corporation would
have the power to indemnify the person against such liabilities under Section
145, including liabilities under the Securities Act.

         Article V of Ecolab's By-Laws provides for indemnification of Ecolab's
officers and directors to the full extent allowed by Delaware law.


                                       4

<PAGE>

         In addition, Article IV of Ecolab's Restated Certificate of
Incorporation provides that Ecolab's directors do not have personal liability to
Ecolab or its stockholders for monetary damages for any breach of their
fiduciary duty as directors, except (1) for a breach of the duty of loyalty, (2)
for acts or omissions not in good faith or which involve intentional misconduct
or knowing violation of the law, (3) for willful or negligent violations of
certain provisions under the General Corporation Law of Delaware imposing
certain requirements with respect to stock repurchases, redemptions and
dividends, or (4) for any transaction from which the director derived an
improper personal benefit. Subject to these exceptions, under Article IV,
directors do not have any personal liability to Ecolab or its stockholders for
any violation of their fiduciary duty.

         Ecolab has directors and officers liability insurance which protects
each director or officer from certain claims and suits, including stockholder
derivative suits, even where the director may be determined to not be entitled
to indemnification under the General Corporation Law of Delaware and claims and
suits arising under the Securities Act. The policy may also afford coverage
under circumstances where the facts do not justify a finding that the director
or officer acted in good faith and in a manner that was in or not opposed to the
best interests of Ecolab.

         Ecolab has entered into indemnification agreements with each of its
directors. These indemnification agreements provide for the prompt
indemnification "to the fullest extent permitted by law" and for the prompt
advancement of expenses, including attorneys' fees and other costs, expenses and
obligations paid or incurred in connection with investigating, defending, being
a witness or participating in (including on appeal) any threatened, pending or
completed action, suit or proceeding related to the fact that the director is or
was a director, officer, employee, trustee, agent or fiduciary of Ecolab or is
or was serving at the request of Ecolab as a director, officer, employee,
trustee, agent or fiduciary of another corporation, partnership, joint venture,
employee benefit plan trust or other enterprise, or by reason of anything done
or not done by a director in any such capacity. The indemnification agreements
further provide that Ecolab has the burden of proving that a director is not
entitled to indemnification in any particular case.

         The foregoing represents a summary of the general effect of the General
Corporation Law of Delaware, Ecolab's By-Laws and Restated Certificate of
Incorporation, Ecolab's directors and officers liability insurance coverage and
the indemnification agreements for purposes of general description only.

ITEM 7.  EXEMPTIONS FROM REGISTRATION CLAIMED.

         Not applicable. No securities are to be re-offered or resold pursuant
to this registration statement.

ITEM 8.  EXHIBITS.

         The following is a complete list of exhibits filed or incorporated by
reference as part of this registration statement:

<TABLE>
<CAPTION>
EXHIBIT NO.          DESCRIPTION
-----------          -----------
<S>               <C>
5.1               Opinion and Consent of Kenneth A. Iverson (filed herewith electronically).

23.1              Consent of PricewaterhouseCoopers LLP (filed herewith electronically).

23.2              Consent of PricewaterhouseCoopers GmbH (filed herewith electronically).

23.3              Consent of Kenneth A. Iverson (included in Exhibit 5.1).

24.1              Powers of Attorney (filed herewith electronically).
</TABLE>


                                       5

<PAGE>

ITEM 9.  UNDERTAKINGS.

     (a)  The undersigned registrant hereby undertakes:

          (1)     To file, during any period in which offers or sales are being
                  made, a post-effective amendment to this registration
                  statement:

                  (i)      To include any prospectus required by Section
                           10(a)(3) of the Securities Act;

                  (ii)     To reflect in the prospectus any facts or events
                           arising after the effective date of this registration
                           statement (or the most recent post-effective
                           amendment hereof) which, individually or in the
                           aggregate, represent a fundamental change in the
                           information set forth in this registration statement.
                           Notwithstanding the foregoing, any increase or
                           decrease in volume of securities offered (if the
                           total dollar value of securities offered would not
                           exceed that which was registered) and any deviation
                           from the low or high end of the estimated maximum
                           offering range may be reflected in the form of
                           prospectus filed with the SEC pursuant to Rule 424(b)
                           under the Securities Act of 1933, as amended if, in
                           the aggregate, the changes in volume and price
                           represent no more than a 20% change in the maximum
                           aggregate offering price set forth in the
                           "Calculation of Registration Fee" table in the
                           effective Registration Statement;

                  (iii)    To include any material information with respect to
                           the plan of distribution not previously disclosed in
                           this Registration Statement or any material change to
                           such information in this Registration Statement.

                  PROVIDED, HOWEVER, that paragraphs (a)(1)(i) and (a)(1)(ii)
                  above do not apply if the information required to be included
                  in a post-effective amendment by those paragraphs is contained
                  in periodic reports filed with or furnished to the SEC by the
                  registrant pursuant to Section 13 or Section 15(d) of the
                  Exchange Act that are incorporated by reference in this
                  Registration Statement.

          (2)     That, for the purpose of determining any liability under the
                  Securities Act, each such post-effective amendment shall be
                  deemed to be a new Registration Statement relating to the
                  securities offered therein, and the offering of such
                  securities at that time shall be deemed to be the initial bona
                  fide offering thereof.

          (3)     To remove from registration by means of a post-effective
                  amendment any of the securities being registered which remain
                  unsold at the termination of the offering.

     (b)  The undersigned registrant hereby undertakes that, for purposes of
          determining any liability under the Securities Act, each filing of the
          registrant's annual report pursuant to Section 13(a) or Section 15(d)
          of the Exchange Act (and where applicable, each filing of an employee
          benefit plan's annual report pursuant to Section 15(d) of the Exchange
          Act) that is incorporated by reference in this Registration Statement
          shall be deemed to be a new Registration Statement relating to the
          securities offered therein, and the offering of such securities at
          that time shall be deemed to be the initial bona fide offering
          thereof.

     (c)  Insofar as indemnification for liabilities arising under the
          Securities Act may be permitted to directors, officers and controlling
          persons of the registrant pursuant to the foregoing provisions, or
          otherwise, the registrant has been advised that in the opinion of the
          SEC such


                                       6

<PAGE>

          indemnification is against public policy as expressed in the
          Securities Act, and is therefore, unenforceable. In the event that a
          claim for indemnification against such liabilities (other than the
          payment by the registrant of expenses incurred or paid by a director,
          officer or controlling person of the registrant in the successful
          defense of any action, suit or proceeding) is asserted by such
          director, officer or controlling person in connection with the
          securities being registered, the registrant will, unless in the
          opinion of its counsel the matter has been settled by controlling
          precedent, submit to a court of appropriate jurisdiction the question
          whether such indemnification by it is against public policy as
          expressed in the Securities Act and will be governed by the final
          adjudication of such issue.


                                       7

<PAGE>

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements of filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of St. Paul, State of Minnesota, on April 5, 2001.


                                          ECOLAB INC.

                                          By: /s/ Allan L. Schuman
                                             ----------------------------------
                                              Allan L. Schuman
                                              CHAIRMAN OF THE BOARD AND
                                              CHIEF EXECUTIVE OFFICER


         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed on April 5, 2001 by the following persons
in the capacities indicated.

SIGNATURE                                       TITLE
----------------------------------------------  -------------------------------

/s/ Allan L. Schuman                            Chairman of the Board and Chief
----------------------------------------------  Executive Officer (principal
Allan L. Schuman                                executive officer) and Director

/s/ L. White Matthews, III                      Executive Vice President and
----------------------------------------------  Chief Financial Officer
L. White Matthews, III                          (principal financial officer)
                                                and Director

/s/ Steven L. Fritze                            Vice President and Controller
----------------------------------------------  (principal accounting officer)
Steven L. Fritze

/s/  Kenneth A. Iverson                         Directors
----------------------------------------------
Kenneth A. Iverson, as attorney-in-fact
for Les S. Biller, Ruth S. Block, Jerry A.
Grundhofer, James J. Howard, William L. Jews,
Joel W. Johnson, Jerry W. Levin, Robert L.
Lumpkins and Hugo Uyterhoeven

Directors not signing
---------------------
Stefan Hamelmann
Ulrich Lehner


                                       8

<PAGE>

                                   ECOLAB INC.
                       REGISTRATION STATEMENT ON FORM S-8

                                INDEX TO EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT NO.   ITEM                                                          METHOD OF FILING
-----------   -----------------------------------------------------------   ------------------------------
<S>           <C>                                                           <C>
5.1           Opinion and Consent of Kenneth A. Iverson..................   Filed herewith electronically.

23.1          Consent of PricewaterhouseCoopers LLP......................   Filed herewith electronically.

23.2          Consent of Consent of PricewaterhouseCoopers GmbH..........   Filed herewith electronically.

23.3          Consent of Kenneth A. Iverson..............................   Included in Exhibit 5.1.

24.1          Powers of Attorney.........................................   Filed herewith electronically.
</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "a2044435zs-8.txt", "description": "S-8", "secsgml_size_bytes": 27396}]
{"company-data": {"conformed-name": "ECOLAB INC", "cik": "0000031462", "assigned-sic": "2840", "irs-number": "410231510", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-58360", "film-number": "1596451"}, "business-address": {"street1": "ECOLAB CTR", "street2": "370 N WABASHA ST", "city": "ST PAUL", "state": "MN", "zip": "55102", "phone": "6122932233"}, "former-company": {"former-conformed-name": "ECONOMICS LABORATORY INC", "date-changed": "19861203"}}
As filed with the Securities and Exchange Commission on April 5, 2001

                                                     Registration No. 333-______
================================================================================

                     U.S. SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             -----------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                        UNDER THE SECURITIES ACT OF 1933

                             -----------------------

                                   ECOLAB INC.
             (Exact name of registrant as specified in its charter)

                  DELAWARE                               41-0231510
       (State or Other Jurisdiction of                 (I.R.S. Employer
       Incorporation or Organization)                Identification No.)

                ECOLAB CENTER
          270 NORTH WABASHA STREET
             ST. PAUL, MINNESOTA                            55102
  (Address of Principal Executive Offices)               (Zip Code)

                             -----------------------

                     ECOLAB INC. 2001 NON-EMPLOYEE DIRECTOR
                   STOCK OPTION AND DEFERRED COMPENSATION PLAN
                            (Full Title of the Plan)

                             -----------------------

                            KENNETH A. IVERSON, ESQ.
                          VICE PRESIDENT AND SECRETARY
                                   ECOLAB INC.
                                  ECOLAB CENTER
                            370 NORTH WABASHA STREET
                            ST. PAUL, MINNESOTA 55102
                                 (651) 293-2125
                      (Name, address and telephone number,
                   including area code, of agent for service)

                            -------------------------

        APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
           IMMEDIATELY UPON THE FILING OF THIS REGISTRATION STATEMENT

                            ------------------------

                         CALCULATION OF REGISTRATION FEE
====================================================================================================================
   TITLE OF SECURITIES        AMOUNT TO BE         PROPOSED MAXIMUM           PROPOSED MAXIMUM          AMOUNT OF
     TO BE REGISTERED       REGISTERED(1)(2)   OFFERING PRICE PER UNIT(3) AGGREGATE OFFERING PRICE  REGISTRATION FEE
--------------------------------------------------------------------------------------------------------------------
Common stock, par value
$1.00 per share(4)               500,000                $41.00                 $20,500,000.00           $5,125.00
====================================================================================================================
(1)  This registration statement is also deemed, pursuant to Instruction E to
     Form S-8, to relate to (a) 206,600 shares of the 250,000 shares that had
     been previously registered on Form S-8 (File No. 333-21167) in connection
     with the Ecolab Inc. 1997 Non-Employee Director Deferred Compensation Plan,
     with respect to which a fee of $1,152.35 has been previously paid, and (b)
     118,400 shares of the 400,000 shares that had been previously registered on
     Form S-8 (File No. 33-59431) in connection with the Ecolab Inc. 1995
     Non-Employee Director Stock Option Plan, with respect to which a fee of
     $473.35 has been previously paid.
(2)  In addition, pursuant to Rule 416(a) under the Securities Act of 1933, as
     amended (the "Securities Act"), this Registration Statement also covers an
     indeterminate number of additional shares of common stock to be offered or
     sold as a result of the anti-dilution provisions of the employee benefit
     plan described in this Registration Statement.

(3)  Estimated solely for the purpose of calculating the registration fee in
     accordance with Rule 457(h)(1) and (c) under the Securities Act, based upon
     the average of the high and low sale prices of the registrant's common
     stock on April 3, 2001, as reported on the Consolidated Transaction
     Reporting System of The New York Stock Exchange.

(4) Each share of common stock includes one-half share of a preferred stock
    purchase right.
EXPLANATORY NOTE

         On February 5, 1997, a total of 125,000 shares (250,000 shares after
adjusting for a January 15, 1998 2-for-1 split) of the common stock (with
preferred stock purchase rights) of Ecolab Inc. ("Ecolab") were registered with
the Securities and Exchange Commission ("SEC") by a Registration Statement on
Form S-8 (File No. 333-21167) in connection with the Ecolab Inc. 1997
Non-Employee Director Deferred Compensation Plan. On May 18, 1995, a total of
200,000 shares (400,000 shares after adjusting for Ecolab's January 15, 1998
2-for-1 stock split) of Ecolab's common stock (with preferred stock purchase
rights) were registered with the Securities and Exchange Commission by a
Registration Statement on Form S-8 (File No. 33-59431) in connection with the
Ecolab Inc. 1995 Non-Employee Director Stock Option Plan. On February 23, 2001,
the Board of Directors of Ecolab approved the Ecolab Inc. 2001 Non-Employee
Director Stock Option and Deferred Compensation Plan, which replaces the Ecolab
Inc. 1997 Non-Employee Director Deferred Compensation Plan and the Ecolab Inc.
1995 Non-Employee Director Stock Option Plan. As of April 5, 2001, 206,600
shares of Ecolab's common stock registered under the Ecolab Inc. 1997
Non-Employee Director Deferred Compensation Plan and 118,400 shares of Ecolab's
common stock registered under the Ecolab Inc. 1995 Non-Employee Director Stock
Option Plan had not been issued under these plans and were not subject to
currently outstanding stock options. Pursuant to Instruction E to Form S-8 and
the telephonic interpretation of the Securities and Exchange Commission
pertaining to "Form S-8" set forth in the Division of Corporation Finance's
Telephone Interpretation Manual of Publicly-Available Telephone Interpretations
(July 1997), as supplemented from time to time thereafter, these remaining and
unissued shares are carried forward and deemed covered by this Registration
Statement on Form S-8 in connection with the Ecolab Inc. 2001 Non-Employee
Director Stock Option and Deferred Compensation Plan.

                                       1
PART I

                              INFORMATION REQUIRED
                         IN THE SECTION 10(a) PROSPECTUS

         The documents containing the information specified in Part I of Form
S-8 have been or will be sent or given to participants as specified by Rule
428(b)(1) under the Securities Act.

                                       2
PART II

                              INFORMATION REQUIRED
                          IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         The following documents filed by Ecolab (File No. 1-9328) with the SEC
are incorporated by reference in this Registration Statement:

         (1)      Annual report on Form 10-K for the year ended December 31,
                  2000;

         (2)      Current reports on Form 8-K dated January 16, 2001 and January
                  24, 2001;

         (3)      All other reports filed by Ecolab pursuant to Section 13(a) or
                  15(d) of the Securities Exchange Act of 1934, as amended (the
                  "Exchange Act"), since December 31, 2000; and

         (4)      The descriptions of Ecolab's common stock, preferred stock and
                  preferred stock purchase rights contained in its registration
                  statements on Form 8-A, including any amendments or reports
                  filed for the purpose of updating these descriptions.

         All documents filed by Ecolab with the SEC pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act after the date of this Registration
Statement and prior to the filing of a post-effective amendment which indicates
that all securities offered pursuant to this Registration Statement have been
sold or that deregisters all securities then remaining unsold, will be deemed to
be incorporated by reference in this Registration Statement and to be a part of
this Registration Statement from the date of filing of these documents.

         The consolidated financial statements and related financial statement
schedule of Ecolab, which are included or incorporated by reference in Ecolab's
Annual Report on Form 10-K for the year ended December 31, 2000, and
incorporated by reference in this Registration Statement, have been audited by
PricewaterhouseCoopers LLP, independent accountants, for the periods indicated
in such firm's reports thereon. The consolidated financial statements and
financial statement schedule audited by PricewaterhouseCoopers LLP have been
incorporated herein by reference in reliance on such firm's reports given upon
their authority as experts in accounting and auditing. To the extent that
PricewaterhouseCoopers LLP examines and reports on the financial statements and
financial statement schedules of Ecolab issued at future dates, and consents to
the use of their reports thereon, such financial statements and financial
statement schedules will also be incorporated by reference in this Registration
Statement in reliance upon their reports and said authority.

         In addition, the combined financial statements and related financial
statement schedule of Henkel-Ecolab, which are included in Ecolab's Annual
Report on Form 10-K for the year ended December 31, 2000, and incorporated by
reference in this Registration Statement, have been audited by
PricewaterhouseCoopers Gesellschaft mit beschrankter Haftung
Wirtschaftsprufungsgesellschaft, independent accountants. The combined financial
statements and related financial statement schedule audited by
PricewaterhouseCoopers Gesellschaft mit beschrankter Haftung
Wirtschaftsprufungsgesellschaft have been incorporated herein by reference in
reliance on such firm's reports given upon their authority as experts in
accounting and auditing. To the extent that PricewaterhouseCoopers Gesellschaft
mit beschrankter Haftung Wirtschaftsprufungsgesellschaft examines and reports on
the financial statements and financial statement schedules of Henkel-Ecolab
issued at future dates, and consents to the use of their reports thereon, such
financial statements and

                                       3
financial statement schedules will also be incorporated by reference in this
Registration Statement in reliance upon their reports and said authority.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable. Ecolab's common stock and preferred stock purchase
rights to be offered and sold pursuant to this registration statement are
registered under Section 12 of the Exchange Act.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Not applicable.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Subsection (a) of Section 145 of the General Corporation Law of
Delaware empowers a corporation to indemnify any person who was or is a party or
is threatened to be made a party to any threatened, pending or completed action,
suit or proceeding, whether civil, criminal, administrative or investigative
(other than an action by or in the right of the corporation), by reason of the
fact that such person is or was a director, officer, employee or agent of the
corporation or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation or enterprise,
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement actually and reasonably incurred by such person in connection with
such action, suit or proceeding if such person acted in good faith and in a
manner such person reasonably believed to be in or not opposed to the best
interests of the corporation, and with respect to any criminal action or
proceeding, had no reasonable cause to believe such person's conduct was
unlawful.

         Subsection (b) of Section 145 empowers a corporation to indemnify any
person who was or is a party or threatened to be made a party to any threatened,
pending or completed action or suit by or in the right of the corporation to
procure a judgment in its favor by reason of the fact that such person acted in
any of the capacities set forth above, against expenses actually and reasonably
incurred by such person in connection with the defense or settlement of such
action or suit if such person acted under similar standards, except that no
indemnification may be made in respect of any claim, issue or matter as to which
such person shall have been adjudged to be liable to the corporation unless and
only to the extent that the Court of Chancery or the court in which the action
or suit was brought shall determine that, despite the adjudication of liability,
the person is fairly and reasonably entitled to indemnity for the expenses which
the court shall deem proper.

         Section 145 further provides that, to the extent a director or officer
of a corporation has been successful in the defense of any action, suit or
proceeding referred to in subsections (a) and (b) or in the defense of any
claim, issue or matter therein, the person shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred in connection
therewith; that indemnification provided for by Section 145 shall not be deemed
exclusive of any other rights to which the indemnified party may be entitled;
and that the scope of indemnification extends to directors, officers, employees
or agents of a constituent corporation absorbed in a consolidation or merger and
persons serving in that capacity at the request of the constituent corporation
for another. Section 145 also empowers the corporation to purchase and maintain
insurance on behalf of a director or officer of the corporation against any
liability asserted against or incurred by the person in any such capacity or
arising out of the person's status as such, whether or not the corporation would
have the power to indemnify the person against such liabilities under Section
145, including liabilities under the Securities Act.

         Article V of Ecolab's By-Laws provides for indemnification of Ecolab's
officers and directors to the full extent allowed by Delaware law.

                                       4
In addition, Article IV of Ecolab's Restated Certificate of
Incorporation provides that Ecolab's directors do not have personal liability to
Ecolab or its stockholders for monetary damages for any breach of their
fiduciary duty as directors, except (1) for a breach of the duty of loyalty, (2)
for acts or omissions not in good faith or which involve intentional misconduct
or knowing violation of the law, (3) for willful or negligent violations of
certain provisions under the General Corporation Law of Delaware imposing
certain requirements with respect to stock repurchases, redemptions and
dividends, or (4) for any transaction from which the director derived an
improper personal benefit. Subject to these exceptions, under Article IV,
directors do not have any personal liability to Ecolab or its stockholders for
any violation of their fiduciary duty.

         Ecolab has directors and officers liability insurance which protects
each director or officer from certain claims and suits, including stockholder
derivative suits, even where the director may be determined to not be entitled
to indemnification under the General Corporation Law of Delaware and claims and
suits arising under the Securities Act. The policy may also afford coverage
under circumstances where the facts do not justify a finding that the director
or officer acted in good faith and in a manner that was in or not opposed to the
best interests of Ecolab.

         Ecolab has entered into indemnification agreements with each of its
directors. These indemnification agreements provide for the prompt
indemnification "to the fullest extent permitted by law" and for the prompt
advancement of expenses, including attorneys' fees and other costs, expenses and
obligations paid or incurred in connection with investigating, defending, being
a witness or participating in (including on appeal) any threatened, pending or
completed action, suit or proceeding related to the fact that the director is or
was a director, officer, employee, trustee, agent or fiduciary of Ecolab or is
or was serving at the request of Ecolab as a director, officer, employee,
trustee, agent or fiduciary of another corporation, partnership, joint venture,
employee benefit plan trust or other enterprise, or by reason of anything done
or not done by a director in any such capacity. The indemnification agreements
further provide that Ecolab has the burden of proving that a director is not
entitled to indemnification in any particular case.

         The foregoing represents a summary of the general effect of the General
Corporation Law of Delaware, Ecolab's By-Laws and Restated Certificate of
Incorporation, Ecolab's directors and officers liability insurance coverage and
the indemnification agreements for purposes of general description only.

ITEM 7.  EXEMPTIONS FROM REGISTRATION CLAIMED.

         Not applicable. No securities are to be re-offered or resold pursuant
to this registration statement.

ITEM 8.  EXHIBITS.

         The following is a complete list of exhibits filed or incorporated by
reference as part of this registration statement:
EXHIBIT NO.          DESCRIPTION
-----------          -----------
5.1               Opinion and Consent of Kenneth A. Iverson (filed herewith electronically).

23.1              Consent of PricewaterhouseCoopers LLP (filed herewith electronically).

23.2              Consent of PricewaterhouseCoopers GmbH (filed herewith electronically).

23.3              Consent of Kenneth A. Iverson (included in Exhibit 5.1).

24.1              Powers of Attorney (filed herewith electronically).
5
ITEM 9.  UNDERTAKINGS.

     (a)  The undersigned registrant hereby undertakes:

          (1)     To file, during any period in which offers or sales are being
                  made, a post-effective amendment to this registration
                  statement:

                  (i)      To include any prospectus required by Section
                           10(a)(3) of the Securities Act;

                  (ii)     To reflect in the prospectus any facts or events
                           arising after the effective date of this registration
                           statement (or the most recent post-effective
                           amendment hereof) which, individually or in the
                           aggregate, represent a fundamental change in the
                           information set forth in this registration statement.
                           Notwithstanding the foregoing, any increase or
                           decrease in volume of securities offered (if the
                           total dollar value of securities offered would not
                           exceed that which was registered) and any deviation
                           from the low or high end of the estimated maximum
                           offering range may be reflected in the form of
                           prospectus filed with the SEC pursuant to Rule 424(b)
                           under the Securities Act of 1933, as amended if, in
                           the aggregate, the changes in volume and price
                           represent no more than a 20% change in the maximum
                           aggregate offering price set forth in the
                           "Calculation of Registration Fee" table in the
                           effective Registration Statement;

                  (iii)    To include any material information with respect to
                           the plan of distribution not previously disclosed in
                           this Registration Statement or any material change to
                           such information in this Registration Statement.

                  PROVIDED, HOWEVER, that paragraphs (a)(1)(i) and (a)(1)(ii)
                  above do not apply if the information required to be included
                  in a post-effective amendment by those paragraphs is contained
                  in periodic reports filed with or furnished to the SEC by the
                  registrant pursuant to Section 13 or Section 15(d) of the
                  Exchange Act that are incorporated by reference in this
                  Registration Statement.

          (2)     That, for the purpose of determining any liability under the
                  Securities Act, each such post-effective amendment shall be
                  deemed to be a new Registration Statement relating to the
                  securities offered therein, and the offering of such
                  securities at that time shall be deemed to be the initial bona
                  fide offering thereof.

          (3)     To remove from registration by means of a post-effective
                  amendment any of the securities being registered which remain
                  unsold at the termination of the offering.

     (b)  The undersigned registrant hereby undertakes that, for purposes of
          determining any liability under the Securities Act, each filing of the
          registrant's annual report pursuant to Section 13(a) or Section 15(d)
          of the Exchange Act (and where applicable, each filing of an employee
          benefit plan's annual report pursuant to Section 15(d) of the Exchange
          Act) that is incorporated by reference in this Registration Statement
          shall be deemed to be a new Registration Statement relating to the
          securities offered therein, and the offering of such securities at
          that time shall be deemed to be the initial bona fide offering
          thereof.

     (c)  Insofar as indemnification for liabilities arising under the
          Securities Act may be permitted to directors, officers and controlling
          persons of the registrant pursuant to the foregoing provisions, or
          otherwise, the registrant has been advised that in the opinion of the
          SEC such

                                       6
indemnification is against public policy as expressed in the
          Securities Act, and is therefore, unenforceable. In the event that a
          claim for indemnification against such liabilities (other than the
          payment by the registrant of expenses incurred or paid by a director,
          officer or controlling person of the registrant in the successful
          defense of any action, suit or proceeding) is asserted by such
          director, officer or controlling person in connection with the
          securities being registered, the registrant will, unless in the
          opinion of its counsel the matter has been settled by controlling
          precedent, submit to a court of appropriate jurisdiction the question
          whether such indemnification by it is against public policy as
          expressed in the Securities Act and will be governed by the final
          adjudication of such issue.

                                       7
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements of filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of St. Paul, State of Minnesota, on April 5, 2001.

                                          ECOLAB INC.

                                          By: /s/ Allan L. Schuman
                                             ----------------------------------
                                              Allan L. Schuman
                                              CHAIRMAN OF THE BOARD AND
                                              CHIEF EXECUTIVE OFFICER

         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed on April 5, 2001 by the following persons
in the capacities indicated.

SIGNATURE                                       TITLE
----------------------------------------------  -------------------------------

/s/ Allan L. Schuman                            Chairman of the Board and Chief
----------------------------------------------  Executive Officer (principal
Allan L. Schuman                                executive officer) and Director

/s/ L. White Matthews, III                      Executive Vice President and
----------------------------------------------  Chief Financial Officer
L. White Matthews, III                          (principal financial officer)
                                                and Director

/s/ Steven L. Fritze                            Vice President and Controller
----------------------------------------------  (principal accounting officer)
Steven L. Fritze

/s/  Kenneth A. Iverson                         Directors
----------------------------------------------
Kenneth A. Iverson, as attorney-in-fact
for Les S. Biller, Ruth S. Block, Jerry A.
Grundhofer, James J. Howard, William L. Jews,
Joel W. Johnson, Jerry W. Levin, Robert L.
Lumpkins and Hugo Uyterhoeven

Directors not signing
---------------------
Stefan Hamelmann
Ulrich Lehner

                                       8
ECOLAB INC.
                       REGISTRATION STATEMENT ON FORM S-8

                                INDEX TO EXHIBITS
EXHIBIT NO.   ITEM                                                          METHOD OF FILING
-----------   -----------------------------------------------------------   ------------------------------
5.1           Opinion and Consent of Kenneth A. Iverson..................   Filed herewith electronically.

23.1          Consent of PricewaterhouseCoopers LLP......................   Filed herewith electronically.

23.2          Consent of Consent of PricewaterhouseCoopers GmbH..........   Filed herewith electronically.

23.3          Consent of Kenneth A. Iverson..............................   Included in Exhibit 5.1.

24.1          Powers of Attorney.........................................   Filed herewith electronically.