-----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,
 Rm7jmnXiwM/lvriaKZJhDNfErvh79r5kXH1QklxwYVYm1CcKGI0mKgv96mQibCfQ
 L8ZPt6uNpMl1D/LAqDa8aA==

<SEC-DOCUMENT>0001104706-04-000004.txt : 20041109
<SEC-HEADER>0001104706-04-000004.hdr.sgml : 20041109
<ACCEPTANCE-DATETIME>20041109150401
ACCESSION NUMBER:		0001104706-04-000004
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041109
FILED AS OF DATE:		20041109
DATE AS OF CHANGE:		20041109

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:			EISEN HARVEY P
		CENTRAL INDEX KEY:			0001104706

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50587
		FILM NUMBER:		041129135

	BUSINESS ADDRESS:	
		STREET 1:		100 SOUTH BEDFORD ROAD
		CITY:			MT KISCO
		STATE:			NY
		ZIP:			10549
		BUSINESS PHONE:		9142425725

	MAIL ADDRESS:	
		STREET 1:		100 SOUTH BEDFORD ROAD
		CITY:			MT KISCO
		STATE:			NY
		ZIP:			10549
</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>2004-11-09</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001104706</rptOwnerCik>
            <rptOwnerName>EISEN HARVEY P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 SOUTH BEDFORD ROARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MOUNT KISCO</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10549</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>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Harvey P. Eisen</signatureName>
        <signatureDate>2004-11-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

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