<SEC-DOCUMENT>0001225208-12-013914.txt : 20120606
<SEC-HEADER>0001225208-12-013914.hdr.sgml : 20120606
<ACCEPTANCE-DATETIME>20120606162424
ACCESSION NUMBER:		0001225208-12-013914
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120604
FILED AS OF DATE:		20120606
DATE AS OF CHANGE:		20120606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GATES WILLIAM H III
		CENTRAL INDEX KEY:			0000902012

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09328
		FILM NUMBER:		12892310

	MAIL ADDRESS:	
		STREET 1:		ONE MICROSOFT WAY
		CITY:			REDMOND
		STATE:			WA
		ZIP:			98052

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ECOLAB INC
		CENTRAL INDEX KEY:			0000031462
		STANDARD INDUSTRIAL CLASSIFICATION:	SOAP, DETERGENT, CLEANING PREPARATIONS, PERFUMES, COSMETICS [2840]
		IRS NUMBER:				410231510
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ECOLAB CORPORATE CENTER
		STREET 2:		370 WABASHA STREET NORTH
		CITY:			ST PAUL
		STATE:			MN
		ZIP:			55102
		BUSINESS PHONE:		6512932233

	MAIL ADDRESS:	
		STREET 1:		ECOLAB CORPORATE CENTER
		STREET 2:		370 WABASHA STREET NORTH
		CITY:			ST. PAUL
		STATE:			MN
		ZIP:			55102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ECONOMICS LABORATORY INC
		DATE OF NAME CHANGE:	19861203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CASCADE INVESTMENT LLC
		CENTRAL INDEX KEY:			0001052192
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09328
		FILM NUMBER:		12892309

	BUSINESS ADDRESS:	
		STREET 1:		2365 CARILLON POINT
		CITY:			KIRKLAND
		STATE:			WA
		ZIP:			98033
		BUSINESS PHONE:		4258030720

	MAIL ADDRESS:	
		STREET 1:		2365 CARILLON POINT
		CITY:			KIRKLAND
		STATE:			WA
		ZIP:			98033
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0305</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-06-04</periodOfReport>

    <issuer>
        <issuerCik>0000031462</issuerCik>
        <issuerName>ECOLAB INC</issuerName>
        <issuerTradingSymbol>ECL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000902012</rptOwnerCik>
            <rptOwnerName>GATES WILLIAM H III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE MICROSOFT WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>REDMOND</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98052</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See footnotes (2) and (3)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001052192</rptOwnerCik>
            <rptOwnerName>CASCADE INVESTMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2365 CARILLON POINT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>KIRKLAND</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98033</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOther>1</isOther>
            <otherText>See footnote (2)</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-06-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>526707.0000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>61.7922</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27911711.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Cascade Investment, L.L.C.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $61.45 to $61.98.  The price set forth above reflects the weighted-average price per share. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.</footnote>
        <footnote id="F2">For purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended (the &quot;Act&quot;), Mr. Gates, as the sole member of Cascade Investment, L.L.C. (&quot;Cascade&quot;) and co-trustee of Bill &amp; Melinda Gates Foundation Trust (&quot;Trust&quot;), may be deemed to beneficially own more than 10% of the common stock of the Issuer.   Mr. Gates has no pecuniary interest in the shares held by the Trust.  Neither the filing of this Form 4 nor any of its contents shall be deemed an admission that Mr. Gates and any other person or persons constitute a &quot;group&quot; under Section 13(d) and Mr. Gates expressly disclaims membership in a group.</footnote>
        <footnote id="F3">For purposes of Section 13(d) of the Act, Cascade may be deemed to be a member of a &quot;group&quot; that beneficially owns more than 10% of the common stock of the Issuer.  Neither the filing of this Form 4 nor any of its contents shall be deemed an admission that Cascade and any other person or persons constitute a &quot;group&quot; under Section 13(d) or is otherwise subject to Section 16 of the Act and Cascade expressly disclaims membership in a group.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alan Heuberger, Attorney-in-fact for William H. Gates III</signatureName>
        <signatureDate>2012-06-06</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Cascade Investment, L.L.C. by Alan Heuberger as attorney-in-fact for Michael Larson, Business Manager</signatureName>
        <signatureDate>2012-06-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
