FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * LEWIS DIANA D   2. Issuer Name and Ticker or Trading Symbol ECOLAB INC [ECL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) SVP - Human Resources (Last) (First) (Middle) ECOLAB INC., 370 WABASHA STREET N. 3. Date of Earliest Transaction (Month/Day/Year) 12/13/2005 (Street) ST. PAUL, MN 55102 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 12/13/2005   M   20,000 A $ 7.594 113,490.704 D   Common Stock 12/13/2005   S   700 D $ 35.21 112,790.704 D   Common Stock 12/13/2005   S   19,300 D $ 35.2 93,490.704 D   Common Stock               11,531.879 (1) I By Ecolab Savings Plan

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Employee Stock Option (right to buy)

$ 7.594 (2)

12/13/2005

M

20,000 (2)

08/16/1997(2)

08/16/2006

Common Stock

20,000

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
LEWIS DIANA D ECOLAB INC. 370 WABASHA STREET N. ST. PAUL, MN 55102			SVP - Human Resources

Signatures

/s/David F. Duvick, Attorney-in-Fact for Diana D. Lewis		12/14/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of November 30, 2005. (The 11,531.879 UNITS are the equivalent of approximately 20,118.624 SHARES of the issuer's Common Stock.)
(2)	Option granted under the Ecolab Inc. 1993 Stock Incentive Plan on August 16, 1996. The option was originally reported as covering 10,000 shares at an exercise price of $15.1875 per share, but has been adjusted to reflect a stock split on June 6, 2003. The option became exercisable as to 25% of the total shares subject to the option (excluding any fractional portion less than one share), on each of the first, second and third anniversaries of the date of grant and as to the remaining shares on the fourth anniversary of the date of grant.

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