-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Nw0zVLCmcajP7Rt4gLZpt/MADN9/YiQ/TQpeZIvG/H541ilKOuuGSGPHEAq5vDHb
 qJJ0cIzUsjco2WVV9raErA==

<SEC-DOCUMENT>0001209191-08-038013.txt : 20080619
<SEC-HEADER>0001209191-08-038013.hdr.sgml : 20080619
<ACCEPTANCE-DATETIME>20080619145412
ACCESSION NUMBER:		0001209191-08-038013
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080616
FILED AS OF DATE:		20080619
DATE AS OF CHANGE:		20080619

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COGNEX CORP
		CENTRAL INDEX KEY:			0000851205
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INSTRUMENTS FOR MEASUREMENT, DISPLAY, AND CONTROL [3823]
		IRS NUMBER:				042713778
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE VISION DR
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760
		BUSINESS PHONE:		5086503000

	MAIL ADDRESS:	
		STREET 1:		ONE VISION DRIVE
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Willett Robert
		CENTRAL INDEX KEY:			0001438093

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-17869
		FILM NUMBER:		08907607

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		508-650-3000

	MAIL ADDRESS:	
		STREET 1:		C/O COGNEX CORPORATION
		STREET 2:		ONE VISION DRIVE
		CITY:			NATICK
		STATE:			MA
		ZIP:			01760-2059
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc3.xml
<DESCRIPTION>FORM 3 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2008-06-16</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000851205</issuerCik>
        <issuerName>COGNEX CORP</issuerName>
        <issuerTradingSymbol>CGNX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001438093</rptOwnerCik>
            <rptOwnerName>Willett Robert</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O COGNEX CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE VISION DRIVE</rptOwnerStreet2>
            <rptOwnerCity>NATICK</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01760</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Exec. VP President of MVSD Div</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>No securities owned</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks>Reporting Person may be deemed to be a member of a 13(d) group that collectively is a ten percent (10%) owner (see that certain Schedule 13(d) filed on May 23, 2008 by Reporting Person and others with respect to the Issuer).  Reporting Person disclaims the existence of a 13(d) group and this Statement shall not be deemed an admission that such group exists.</remarks>

    <ownerSignature>
        <signatureName>/s/ Robert Willett</signatureName>
        <signatureDate>2008-06-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
