FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF 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 *   Inchaustegui Roberto 2. Date of Event Requiring Statement (Month/Day/Year) 05/05/2011 3. Issuer Name and Ticker or Trading Symbol ECOLAB INC [ECL] (Last) (First) (Middle) 370 WABASHA STREET NORTH 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP-Global Specialty Sector 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) ST. PAUL, MN 55102 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 Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 1,485 D   Common Stock 6.047 (9) I By Ecolab Savings Plan

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right to Buy)	12/09/2005(1)	12/09/2014	Common Stock	13,600	$ 34.5	D	Â
Employee Stock Option (Right to Buy)	12/07/2006(2)	12/07/2015	Common Stock	13,500	$ 34.075	D	Â
Employee Stock Option (Right to Buy)	12/06/2007(3)	12/06/2016	Common Stock	10,300	$ 45.24	D	Â
Employee Stock Option (Right to Buy)	12/05/2008(4)	12/05/2017	Common Stock	12,200	$ 49.42	D	Â
Employee Stock Option (Right to Buy)	07/31/2009(5)	07/31/2018	Common Stock	37,000	$ 44.91	D	Â
Employee Stock Option (Right to Buy)	12/03/2009(6)	12/03/2018	Common Stock	19,700	$ 35.63	D	Â
Employee Stock Option (Right to Buy)	12/02/2010(7)	12/02/2019	Common Stock	9,600	$ 45.665	D	Â
Employee Stock Option (Right to Buy)	12/01/2011(8)	12/01/2020	Common Stock	10,600	$ 48.055	D	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Inchaustegui Roberto 370 WABASHA STREET NORTH ST. PAUL, MN 55102	Â	Â	  EVP-Global Specialty Sector	Â

Signatures

David F. Duvick, as Attorney-in-Fact for Roberto Inchaustegui		05/09/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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)	Option granted under the Ecolab Inc. 2002 Stock Incentive Plan on December 9, 2004. The option became exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(2)	Option granted under the Ecolab Inc. 2002 Stock Incentive Plan on December 7, 2005. The option became exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(3)	Option granted under the Ecolab Inc. 2002 Stock Incentive Plan on December 6, 2006. The option became exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(4)	Option granted under the Ecolab Inc. 2005 Stock Incentive Plan on December 5, 2007. The option became exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(5)	Option granted under the Ecolab Inc. 2005 Stock Incentive Plan on July 31, 2008. The option becomes exercisableas to 100% of the option shares on the fourth anniversary of the date of grant.
(6)	Option granted under the Ecolab Inc. 2005 Stock Incentive Plan on December 3, 2008. The option will become exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(7)	Option granted under the Ecolab Inc. 2005 Stock Incentive Plan on December 2, 2009. The option will become exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(8)	Option granted under the Ecolab Inc. 2010 Stock Incentive Plan on December 1, 2010. The option will become exercisable, on a cumulative basis, as to one-third of the option shares (excluding any fractional portion less than one share), on each of the first and second anniversaries of the date of grant and as to the remaining option shares on the third anniversary of the date of grant.
(9)	Number of UNITS in the Ecolab Stock Fund of the Ecolab Savings Plan (401(k) Plan) as of May 4, 2011. (The 6.047 UNITS are the equivalent of approximtely 11 shares of the issuer's Common Stock.)

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