-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 VAtVDUmQ7DzasUhtfy1kE22KE3t3tugL0KqrLwMCtiFzs0Kt/TmZwVAXdCFCQZOb
 hIYLIU/KdzD9AWXPORwcWA==

<SEC-DOCUMENT>0000067625-04-000005.txt : 20040209
<SEC-HEADER>0000067625-04-000005.hdr.sgml : 20040209
<ACCEPTANCE-DATETIME>20040209095825
ACCESSION NUMBER:		0000067625-04-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040206
FILED AS OF DATE:		20040209

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MONMOUTH REAL ESTATE INVESTMENT CORP
		CENTRAL INDEX KEY:			0000067625
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				221897375
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		3499 ROUTE 9 N, SUITE 3-C
		STREET 2:		JUNIPER BUSINESS PLAZA
		CITY:			FREEHOLD
		STATE:			NJ
		ZIP:			07728
		BUSINESS PHONE:		7325779996

	MAIL ADDRESS:	
		STREET 1:		3499 ROUTE 9 N, SUITE 3-C
		STREET 2:		JUNIPER BUSINESS PLAZA
		CITY:			FREEHOLD
		STATE:			NJ
		ZIP:			07728

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MONMOUTH REAL ESTATE INVESTMENT TRUST
		DATE OF NAME CHANGE:	19900403

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MORGENSTERN CYNTHIA J
		CENTRAL INDEX KEY:			0001232930

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-04258
		FILM NUMBER:		04576192

	BUSINESS ADDRESS:	
		STREET 1:		3499 ROUTE 9 N STE 3-C
		CITY:			FREEHOLD
		STATE:			NJ
		ZIP:			07728
		BUSINESS PHONE:		7325779997

	MAIL ADDRESS:	
		STREET 1:		3499 ROUTE 9 N STE 3-C
		CITY:			FREEHOLD
		STATE:			NJ
		ZIP:			07728
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-02-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000067625</issuerCik>
        <issuerName>MONMOUTH REAL ESTATE INVESTMENT CORP</issuerName>
        <issuerTradingSymbol>mnrta</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232930</rptOwnerCik>
            <rptOwnerName>MORGENSTERN CYNTHIA J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3499 ROUTE 9 N STE 3-C</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FREEHOLD</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07728</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Monmouth Real Estate Investment Corporation</value>
            </securityTitle>
            <transactionDate>
                <value>2004-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13826.4197</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Monmouth Real Estate Investment Corporation</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.13</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-06-21</value>
            </exerciseDate>
            <expirationDate>
                <value>2010-06-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Monmouth Real Estate Investment Corporation</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>43000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Exercise partial stock option; 7,000 shares of a 50,000 option.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Rosemarie Faccone</signatureName>
        <signatureDate>2004-02-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

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