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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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<SEC-DOCUMENT>0001018207-06-000004.txt : 20060404
<SEC-HEADER>0001018207-06-000004.hdr.sgml : 20060404
<ACCEPTANCE-DATETIME>20060404150639
ACCESSION NUMBER:		0001018207-06-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060331
FILED AS OF DATE:		20060404
DATE AS OF CHANGE:		20060404

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NATIONAL PATENT DEVELOPMENT CORP
		CENTRAL INDEX KEY:			0001279715
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS MANUFACTURING INDUSTRIES [3990]
		IRS NUMBER:				134005439
		STATE OF INCORPORATION:			DE

	BUSINESS ADDRESS:	
		STREET 1:		777 WESTCHESTER AVE.
		STREET 2:		FOURTH FLOOR
		CITY:			WHITE PLAINS
		STATE:			NY
		ZIP:			10640

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HOFFMANN ROALD
		CENTRAL INDEX KEY:			0001018207

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50587
		FILM NUMBER:		06737591

	BUSINESS ADDRESS:	
		STREET 1:		9 WEST 57 ST
		STREET 2:		STE 4170
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		2122309617

	MAIL ADDRESS:	
		STREET 1:		9 WEST 57 STREET
		STREET 2:		SUITE 4170
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-03-31</periodOfReport>

    <issuer>
        <issuerCik>0001279715</issuerCik>
        <issuerName>NATIONAL PATENT DEVELOPMENT CORP</issuerName>
        <issuerTradingSymbol>NPDV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001018207</rptOwnerCik>
            <rptOwnerName>HOFFMANN ROALD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>CORNELL UNIVERSITY</rptOwnerStreet1>
            <rptOwnerStreet2>DEPT. OF CHEMISTRY, BAKER LABORATORY</rptOwnerStreet2>
            <rptOwnerCity>ITHACA</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>14853</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>426</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.47</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5159</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Quarterly Director's Fee</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Lydia M. DeSantis for Roald Hoffmann</signatureName>
        <signatureDate>2006-04-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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