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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 C0Rru6jwFky+RJLR5tQX5tHarZ6Dp8s4so8arvLh9MCEfrh1pWlRUh/QNP/Z9gRx
 mKmHsYoF92FvSfhbSiZwFA==

<SEC-DOCUMENT>0001226579-03-000039.txt : 20030926
<SEC-HEADER>0001226579-03-000039.hdr.sgml : 20030926
<ACCEPTANCE-DATETIME>20030926165049
ACCESSION NUMBER:		0001226579-03-000039
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030919
FILED AS OF DATE:		20030926

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCMURRAY CHARLES J
		CENTRAL INDEX KEY:			0001264974

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07891
		FILM NUMBER:		03912988

	MAIL ADDRESS:	
		STREET 1:		PO BOX 1299
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55440-1299

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>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
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<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType><periodOfReport>2003-09-19</periodOfReport>
    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000029644</issuerCik>
        <issuerName>DONALDSON CO INC</issuerName>
        <issuerTradingSymbol>CDI</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001264974</rptOwnerCik>
            <rptOwnerName>MCMURRAY CHARLES J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1400 WEST 94TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BLOOMINGTON</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55431-2303</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>VP, Human Resources</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2108</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>207</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Benefit Plan Trust</value></natureOfOwnership></ownershipNature></nonDerivati
veHolding><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>9689</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Benefit Plan Trust</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeHolding><securityTitle><value> Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>6.27</value></conversionOrExercisePrice><exerciseDate><value>1992-01-07</value></exerciseDate><expirationDate><value>2002-01-07</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirec
tOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value> Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>16.25</value></conversionOrExercisePrice><exerciseDate><value>1996-12-05</value></exerciseDate><expirationDate><value>2006-12-05</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>22.68</value></conversionOrExercisePrice><exerciseDate><value>1997-12-19</value></exerciseDate><expirationDate><value>2007-12-19</value></e
xpirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>2500</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>20.00</value></conversionOrExercisePrice><exerciseDate><value>1998-12-03</value></exerciseDate><expirationDate><value>2008-12-03</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3500</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeH
olding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>23.00</value></conversionOrExercisePrice><exerciseDate><value>1999-12-06</value></exerciseDate><expirationDate><value>2009-12-06</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>25.81</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F1"/></exerciseDate><expirationDate><value>2010-12-12</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underl
yingSecurityTitle><underlyingSecurityShares><value>3000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>36.38</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F2"/></exerciseDate><expirationDate><value>2011-12-03</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3500</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Employee Stock Option (right to buy)</value></secu
rityTitle><conversionOrExercisePrice><value>35.56</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F3"/></exerciseDate><expirationDate><value>2012-12-05</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>3000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding></derivativeTable><footnotes><footnote id="F1">Option vests in three equal annual installments commencing one year from grant date of 12/12/2000.</footnote><footnote id="F2">Option vests in three equal annual installments commencing one year from grant date of 12/03/2001.</footnote><footnote id="F3">Option vests in three equal annual installments commencing one year from grant date of 12/05/2002.</footnote></footnotes><remarks/><ownerSignature><signatureName>Cha
rles J. McMurray</signatureName><signatureDate>2003-09-26</signatureDate></ownerSignature></ownershipDocument>

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