-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ADI7upZBME2NEdR8Dx2+AnGU7F14Nv3Meut3ODaYnbTrRUwoWT7noeQQ+eGjn93I
 XcIHtaAcWgzRlMHv2MhCoA==

<SEC-DOCUMENT>0001253532-03-000017.txt : 20030912
<SEC-HEADER>0001253532-03-000017.hdr.sgml : 20030912
<ACCEPTANCE-DATETIME>20030912105408
ACCESSION NUMBER:		0001253532-03-000017
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030908
FILED AS OF DATE:		20030912

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CUNO INC
		CENTRAL INDEX KEY:			0001019779
		STANDARD INDUSTRIAL CLASSIFICATION:	GENERAL INDUSTRIAL MACHINERY & EQUIPMENT, NEC [3569]
		IRS NUMBER:				061159240
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		400 RESEARCH PARKWAY
		CITY:			MERIDEN
		STATE:			CT
		ZIP:			06450
		BUSINESS PHONE:		2032375541

	MAIL ADDRESS:	
		STREET 1:		400 RESEARCH PARKWAY
		CITY:			MERIDEN
		STATE:			CT
		ZIP:			06450

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MCLAREN COLIN JOHN
		CENTRAL INDEX KEY:			0001261051

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-21109
		FILM NUMBER:		03893086

	BUSINESS ADDRESS:	
		STREET 1:		400 RESEARCH PARKWAY
		STREET 2:		PO BOX 1018
		CITY:			MERIDEN
		STATE:			CT
		ZIP:			06450 1018
		BUSINESS PHONE:		203 238 8749

	MAIL ADDRESS:	
		STREET 1:		400 RESEARCH PARKWAY
		STREET 2:		PO BOX 1018
		CITY:			MERIDEN
		STATE:			CT
		ZIP:			06450 1018
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2003-09-08</periodOfReport>


    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001019779</issuerCik>
        <issuerName>CUNO INC</issuerName>
        <issuerTradingSymbol>CUNO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001261051</rptOwnerCik>
            <rptOwnerName>MCLAREN COLIN JOHN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>400 RESEARCH PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 1018</rptOwnerStreet2>
            <rptOwnerCity>MERIDEN</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06450 1018</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15.125</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>1998-09-26</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2006-09-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.125</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2000-11-17</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-11-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.75</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-01-11</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-01-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>27.875</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-12-01</value>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-11-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.15</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-12-01</value>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2011-11-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>33</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-12-02</value>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-12-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>37.9</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-07-16</value>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-07-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">Option vests in two equal annual installments beginning September 26, 1998.</footnote>
        <footnote id="F2">Option vests in two equal annual installments beginning November 17, 2000.</footnote>
        <footnote id="F3">Option vests in two equal annual installments beginning January 11, 2002.</footnote>
        <footnote id="F4">Option vests in two equal annual installments beginning December 1. 2002.</footnote>
        <footnote id="F5">Option vests in two equal annual installments beginning December 1, 2003.</footnote>
        <footnote id="F6">Option vests in two equal annual installments beginning December 2, 2004.</footnote>
        <footnote id="F7">Option vests in two equal annual installments beginning July 16, 2005.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>Colin J. McLaren</signatureName>
        <signatureDate>2003-09-12</signatureDate>
    </ownerSignature>

</ownershipDocument>

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