-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 tvBjqakN1rABhXE8F8b7/A==

<SEC-DOCUMENT>0000897101-03-000943.txt : 20030808
<SEC-HEADER>0000897101-03-000943.hdr.sgml : 20030808
<ACCEPTANCE-DATETIME>20030808131537
ACCESSION NUMBER:		0000897101-03-000943
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030410
FILED AS OF DATE:		20030808

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SCHWAB LOWELL F
		CENTRAL INDEX KEY:			0001226581

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07891
		FILM NUMBER:		03830979

	BUSINESS ADDRESS:	
		STREET 1:		C/O DONALDSON CO INC
		STREET 2:		PO BOX 1299
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55440-1299
		BUSINESS PHONE:		9528873631

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DONALDSON CO INC
		CENTRAL INDEX KEY:			0000029644
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL & COMMERCIAL FANS & BLOWERS & AIR PURIFYING EQUIP [3564]
		IRS NUMBER:				410222640
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0731

	BUSINESS ADDRESS:	
		STREET 1:		1400 W. 94TH ST.
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55431
		BUSINESS PHONE:		6128873131

	MAIL ADDRESS:	
		STREET 1:		1400 W 94TH STREET
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55431
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>dci-schwab410_4ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<!-- - EDGAR Ease Plus 1.0                                   07/25/03  TT    -->
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4/A</documentType>
   <periodOfReport>2003-04-10</periodOfReport>
   <dateOfOriginalSubmission>2003-04-10</dateOfOriginalSubmission>
   <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000029644</issuerCik>
        <issuerName>DONALDSON CO INC</issuerName>
        <issuerTradingSymbol>DCI</issuerTradingSymbol>
   </issuer>
   <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001226581</rptOwnerCik>
            <rptOwnerName>SCHWAB LOWELL F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1400 WEST 94TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BLOOMINGTON</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55431</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
         <isDirector>0</isDirector>
         <isOfficer>1</isOfficer>
         <isTenPercentOwner>0</isTenPercentOwner>
         <isOther>0</isOther>
         <officerTitle>Senior VP</officerTitle>
      </reportingOwnerRelationship>
   </reportingOwner>
 <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-04-10</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>21000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>23.00</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>A</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>0</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <transactionDate>
         <value>2003-04-10</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>F</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>16432</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>39.48</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>72913</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
   <nonDerivativeHolding>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>1982</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>I</value>
         </directOrIndirectOwnership>
         <natureOfOwnership>
            <value>By Benefit Plan Trust</value>
         </natureOfOwnership>
      </ownershipNature>
   </nonDerivativeHolding>
   <nonDerivativeHolding>
      <securityTitle>
         <value>Common Stock</value>
      </securityTitle>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>12946</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>I</value>
         </directOrIndirectOwnership>
         <natureOfOwnership>
            <value>By Benefit Plan Trust</value>
         </natureOfOwnership>
      </ownershipNature>
   </nonDerivativeHolding>
 </nonDerivativeTable>
 <derivativeTable>
   <derivativeTransaction>
      <securityTitle>
         <value>Option (right to buy)</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>23.00</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-04-10</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>M</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>21000</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>0</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>1999-12-06</value>
      </exerciseDate>
      <expirationDate>
         <value>2009-12-06</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>21000</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>0</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
   <derivativeTransaction>
      <securityTitle>
         <value>Option (right to buy)</value>
      </securityTitle>
      <conversionOrExercisePrice>
         <value>39.48</value>
      </conversionOrExercisePrice>
      <transactionDate>
         <value>2003-04-10</value>
      </transactionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>A</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>16432</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>0</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>A</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <exerciseDate>
         <value>2003-04-09</value>
            <footnoteId id="F1"/>
      </exerciseDate>
      <expirationDate>
         <value>2009-12-09</value>
      </expirationDate>
      <underlyingSecurity>
         <underlyingSecurityTitle>
           <value>Common Stock</value>
         </underlyingSecurityTitle>
         <underlyingSecurityShares>
           <value>16432</value>
         </underlyingSecurityShares>
      </underlyingSecurity>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>16432</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
           <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </derivativeTransaction>
 </derivativeTable>
   <footnotes>
      <footnote id="F1"> Amendment to add reload shares of 16,432.</footnote>
   </footnotes>
   <ownerSignature>
      <signatureName>Lowell Schwab /s/ Norman C. Linnell by Power of Attorney</signatureName>
      <signatureDate>2003-08-07</signatureDate>
   </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----