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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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 st+Dk2fFmTceKT1wKC74DA==

<SEC-DOCUMENT>0000859475-09-000051.txt : 20091020
<SEC-HEADER>0000859475-09-000051.hdr.sgml : 20091020
<ACCEPTANCE-DATETIME>20091020191659
ACCESSION NUMBER:		0000859475-09-000051
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091017
FILED AS OF DATE:		20091020
DATE AS OF CHANGE:		20091020

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TRIDENT MICROSYSTEMS INC
		CENTRAL INDEX KEY:			0000859475
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				770156584
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		3408 GARRETT DRIVE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054-2803
		BUSINESS PHONE:		4087648808

	MAIL ADDRESS:	
		STREET 1:		3408 GARRETT DRIVE
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054-2803

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Summers Sylvia
		CENTRAL INDEX KEY:			0001347095

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20784
		FILM NUMBER:		091128926

	MAIL ADDRESS:	
		STREET 1:		915 DEGUIGNE DRIVE
		STREET 2:		PO BOX 3453
		CITY:			SUNNYVALE
		STATE:			CA
		ZIP:			940883453
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-10-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000859475</issuerCik>
        <issuerName>TRIDENT MICROSYSTEMS INC</issuerName>
        <issuerTradingSymbol>TRID</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001347095</rptOwnerCik>
            <rptOwnerName>Summers Sylvia</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3408 GARRETT DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054-2803</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-10-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2681</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>281055</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>By: /s/ Chris Siu, Attorney-in-Fact  For: Sylvia Summers</signatureName>
        <signatureDate>2009-10-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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