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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 3kySxCu+P2Uce/iqj2YJ4A==

<SEC-DOCUMENT>0001239383-06-000048.txt : 20061011
<SEC-HEADER>0001239383-06-000048.hdr.sgml : 20061011
<ACCEPTANCE-DATETIME>20061011122059
ACCESSION NUMBER:		0001239383-06-000048
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061002
FILED AS OF DATE:		20061011
DATE AS OF CHANGE:		20061011

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TERADYNE INC
		CENTRAL INDEX KEY:			0000097210
		STANDARD INDUSTRIAL CLASSIFICATION:	INSTRUMENTS FOR MEAS & TESTING OF ELECTRICITY & ELEC SIGNALS [3825]
		IRS NUMBER:				042272148
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		321 HARRISON AVE
		STREET 2:		MAIL STOP H93
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02118
		BUSINESS PHONE:		6174822700

	MAIL ADDRESS:	
		STREET 1:		321 HARRISON AVENUE
		STREET 2:		H93
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02118

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GILLIS EDWIN J
		CENTRAL INDEX KEY:			0001186557

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06462
		FILM NUMBER:		061139552

	BUSINESS ADDRESS:	
		STREET 1:		C/O PARAMETRIC TECHNOLOGY CORP
		STREET 2:		140 KENDRICK ST
		CITY:			NEEDHAM
		STATE:			MA
		ZIP:			02494
		BUSINESS PHONE:		6505274190

	MAIL ADDRESS:	
		STREET 1:		C/O VERITAS SOFTWARE CORP
		STREET 2:		350 ELLIS STREET
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-10-02</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000097210</issuerCik>
        <issuerName>TERADYNE INC</issuerName>
        <issuerTradingSymbol>TER</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186557</rptOwnerCik>
            <rptOwnerName>GILLIS EDWIN J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>600 RIVERPARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NORTH READING</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01864</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options/Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Not Applicable - No derivative securities beneficially owned.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Edwin J. Gillis</signatureName>
        <signatureDate>2006-10-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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