Ownership Submission
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
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(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

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

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.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.