-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 OWwomTdf7BHrwbNPysdd//yVvvPGTE1xb/e/xl+tOBElLoHZRu0U/wq47He0YLNQ
 qilTEYD/Envdn39Ly///aw==

<SEC-DOCUMENT>0000074208-05-000025.txt : 20050222
<SEC-HEADER>0000074208-05-000025.hdr.sgml : 20050221
<ACCEPTANCE-DATETIME>20050222101108
ACCESSION NUMBER:		0000074208-05-000025
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050215
FILED AS OF DATE:		20050222
DATE AS OF CHANGE:		20050222

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Vela Moises V JR
		CENTRAL INDEX KEY:			0001318311

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10524
		FILM NUMBER:		05629591

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		720-283-6120

	MAIL ADDRESS:	
		STREET 1:		1745 SHEA CENTER DRIVE SUITE 200
		CITY:			HIGHLANDS RANCH
		STATE:			CO
		ZIP:			80129

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNITED DOMINION REALTY TRUST INC
		CENTRAL INDEX KEY:			0000074208
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				540857512
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		400 EAST CARY STREET
		CITY:			RICHMOND
		STATE:			VA
		ZIP:			23219-3802
		BUSINESS PHONE:		8047802691

	MAIL ADDRESS:	
		STREET 1:		400 EAST CARY STREET
		CITY:			RICHMOND
		STATE:			VA
		ZIP:			23219-3802

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OLD DOMINION REAL ESTATE INVESTMENT TRUST
		DATE OF NAME CHANGE:	19850110

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OLD DOMINION REIT ONE
		DATE OF NAME CHANGE:	19770921

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OLD DOMINION REAL ESTATE INVESTMENT TRUS
		DATE OF NAME CHANGE:	19741216
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>c0001318311d20050221f3f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2005-02-15</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000074208</issuerCik>
        <issuerName>UNITED DOMINION REALTY TRUST INC</issuerName>
        <issuerTradingSymbol>UDR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001318311</rptOwnerCik>
            <rptOwnerName>Vela Moises V JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>400 EAST CARY STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RICHMOND</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>23219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>MOISES V VELA, JR</signatureName>
        <signatureDate>2005-02-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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