-----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,
 Hnlb6GfzosjBgv3JK5N8RdvrNvlCRA40Ci37P/Rv24wcZTGCg8CYIF4dC5RUoL/Y
 5J4YKCnnHRCPbRFwKuJv+w==

<SEC-DOCUMENT>0001444539-11-000001.txt : 20110211
<SEC-HEADER>0001444539-11-000001.hdr.sgml : 20110211
<ACCEPTANCE-DATETIME>20110211155231
ACCESSION NUMBER:		0001444539-11-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110210
FILED AS OF DATE:		20110211
DATE AS OF CHANGE:		20110211

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Blocher Andrew P
		CENTRAL INDEX KEY:			0001444539

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07533
		FILM NUMBER:		11598890

	MAIL ADDRESS:	
		STREET 1:		1626 EAST JEFFERSON STREET
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20852

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FEDERAL REALTY INVESTMENT TRUST
		CENTRAL INDEX KEY:			0000034903
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				520782497
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1626 EAST JEFFERSON STREET
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20852-4041
		BUSINESS PHONE:		3019988100

	MAIL ADDRESS:	
		STREET 1:		1625 EAST JEFFERSON STREET
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20852-4041
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-02-10</periodOfReport>

    <issuer>
        <issuerCik>0000034903</issuerCik>
        <issuerName>FEDERAL REALTY INVESTMENT TRUST</issuerName>
        <issuerTradingSymbol>FRT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001444539</rptOwnerCik>
            <rptOwnerName>Blocher Andrew P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1626 EAST JEFFERSON STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROCKVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20852</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior VP - CFO &amp; Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common shares of beneficial interest</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3165</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35043.4</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Dawn M. Becker, by power of attorney</signatureName>
        <signatureDate>2011-02-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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