-----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,
 BA5P7IhN7Dhr9QcHdI4s5WnHgZVAvYxk6kzW3n4tLGeNLkxAK+pCE2kd547cFmRq
 aMC7H7/XQ8Ow7LFBBn2Adg==

<SEC-DOCUMENT>0001221504-03-000004.txt : 20030606
<SEC-HEADER>0001221504-03-000004.hdr.sgml : 20030606
<ACCEPTANCE-DATETIME>20030606161138
ACCESSION NUMBER:		0001221504-03-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030605
FILED AS OF DATE:		20030606

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SAXE ROBERT L
		CENTRAL INDEX KEY:			0001221504

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09399
		FILM NUMBER:		03736039

	BUSINESS ADDRESS:	
		STREET 1:		RESEARCH FRONTIERS
		STREET 2:		240 CROSSWAYS PARK DR
		CITY:			WOODBURY
		STATE:			NY
		ZIP:			11797-2033
		BUSINESS PHONE:		5163641902

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RESEARCH FRONTIERS INC
		CENTRAL INDEX KEY:			0000793524
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				112103466
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		240 CROSSWAYS PARK DR
		CITY:			WOODBURY
		STATE:			NY
		ZIP:			11797-2033
		BUSINESS PHONE:		5163641902

	MAIL ADDRESS:	
		STREET 1:		240 CROSSWAYS PARK DR
		CITY:			WOODBURY
		STATE:			NY
		ZIP:			11797-2033
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-06-05</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000793524</issuerCik>
        <issuerName>RESEARCH FRONTIERS INC</issuerName>
        <issuerTradingSymbol>REFR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001221504</rptOwnerCik>
            <rptOwnerName>SAXE ROBERT L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Common Stock</value>
        </securityTitle>
        <transactionDate>
            <value>2003-06-05</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>F</transactionCode>
            <equitySwapInvolved>1</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>5005</value>
                <footnoteId id="F1"/>
            </transactionShares>
            <transactionValue>
                <value>7.2667</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>334557</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <derivativeSecurity>
        <securityTitle>
            <value>Stock Option (right to buy)</value>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>7.2667</value>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-06-05</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>M</transactionCode>
            <equitySwapInvolved>1</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>15000</value>
                <footnoteId id="F1"/>
            </transactionShares>
            <transactionValue>
                <value>7.2667</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>1993-06-10</value>
        </exerciseDate>
        <expirationDate>
            <value>2003-06-09</value>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>15000</value>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>1143975</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">The reported transaction involves the delivery of 9995 previously-owned shares in partial payment of the exercise price of an option to purchase 15,000 shares of common stock at an exercise price of $7.266667 per share, resulting in the net issuance to the reporting person of 5,005 shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Robert L. Saxe</signatureName>
        <signatureDate>2003-06-06</signatureDate>
    </ownerSignature>

</ownershipDocument>

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