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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HucTeYVd3UmTsUTX+GFwrywdlkr5oeQcCtmzZyk4Zylq42UxuMq3HfqK+lhQ+Uax
 czRQcHAcgzok6DY6VZTxkA==

<SEC-DOCUMENT>0001187907-04-000066.txt : 20040415
<SEC-HEADER>0001187907-04-000066.hdr.sgml : 20040415
<ACCEPTANCE-DATETIME>20040415140940
ACCESSION NUMBER:		0001187907-04-000066
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040415
FILED AS OF DATE:		20040415

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			AMATO JOSEPH
		CENTRAL INDEX KEY:			0001187918

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09279
		FILM NUMBER:		04735464

	BUSINESS ADDRESS:	
		STREET 1:		60 CUTTER MILL RD
		STREET 2:		STE 303
		CITY:			GREAT NECK
		STATE:			NY
		ZIP:			11021

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ONE LIBERTY PROPERTIES INC
		CENTRAL INDEX KEY:			0000712770
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				133147497
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		60 CUTTER MILL RD
		STREET 2:		SUITE 303
		CITY:			GREAT NECK
		STATE:			NY
		ZIP:			11021-3190
		BUSINESS PHONE:		5164663100

	MAIL ADDRESS:	
		STREET 1:		60 CUTTER MILL ROAD
		STREET 2:		SUITE 303
		CITY:			GREAT NECK
		STATE:			NY
		ZIP:			11021-3190

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ONE LIBERTY FIRESTONE PROPERTIES INC
		DATE OF NAME CHANGE:	19851112
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-04-15</periodOfReport>

    <issuer>
        <issuerCik>0000712770</issuerCik>
        <issuerName>ONE LIBERTY PROPERTIES INC</issuerName>
        <issuerTradingSymbol>OLP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187918</rptOwnerCik>
            <rptOwnerName>AMATO JOSEPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>615 ROUTE 32, P.O. BOX 503</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HIGHLAND MILLS,</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10930-0503</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>2004-04-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The 1000 shares were awarded to reporting person under the 2003 Incentive Plan.  The vesting date is April 15, 2009.  The award is exempt from Section 16(b) under Rule 16(b)-3.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Joseph A. Amato</signatureName>
        <signatureDate>2004-04-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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