-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 M7BjjMZs1Sh7JiJux1WRCZmuCI1xdQCPyr9hPpXlzOBYVYyQ4HZnlMu12iQC4ZGM
 SqkWx/gUlC5yXMoDgxApdQ==

<SEC-DOCUMENT>0001105577-04-000003.txt : 20040518
<SEC-HEADER>0001105577-04-000003.hdr.sgml : 20040518
<ACCEPTANCE-DATETIME>20040518164835
ACCESSION NUMBER:		0001105577-04-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040514
FILED AS OF DATE:		20040518

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EQUITY RESIDENTIAL
		CENTRAL INDEX KEY:			0000906107
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				363877868
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		EQUITY RESIDENTIAL
		STREET 2:		2 N RIVERSIDE PLAZA, STE 400
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		3129281178

	MAIL ADDRESS:	
		STREET 1:		TWO N RIVERSIDE PLAZA
		STREET 2:		SUITE 450
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EQUITY RESIDENTIAL PROPERTIES TRUST
		DATE OF NAME CHANGE:	19930524

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DUNCAN BRUCE W
		CENTRAL INDEX KEY:			0001105577

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12252
		FILM NUMBER:		04816581

	BUSINESS ADDRESS:	
		STREET 1:		C/O CADILLAC FAIRVIEW CORP 20 QUEEN ST W
		STREET 2:		TORONTO ONTARIO CANADA M5H 3R4
		BUSINESS PHONE:		9146408100

	MAIL ADDRESS:	
		STREET 1:		C/O CADILLAC FAIRVIEW CORP 20 QUEEN ST W
		STREET 2:		TORONTO ONTARIO CANADA M5H 3R4
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001105577d20040518f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000906107</issuerCik>
        <issuerName>EQUITY RESIDENTIAL</issuerName>
        <issuerTradingSymbol>EQR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001105577</rptOwnerCik>
            <rptOwnerName>DUNCAN BRUCE W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>TWO NORTH RIVERSIDE PLAZA, SUITE 400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and Chief Executive</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares of Beneficial Interest</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110421</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares of Beneficial Interest</value>
            </securityTitle>
            <transactionDate>
                <value>2004-05-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>235</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.35</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13494</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>SERP Account</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>23.55</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-02-07</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-02-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares of Beneficial Interest</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>168820</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>168820</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>28.98</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-09-14</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-03-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares of Beneficial Interest</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>28.98</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-03-18</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-03-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares of Beneficial Interest</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>41361</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41361</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.25</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-01-27</value>
            </exerciseDate>
            <expirationDate>
                <value>2014-01-27</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares of Beneficial Interest</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>283464</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>283464</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Operating Partnership Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-03-14</value>
            </exerciseDate>
            <expirationDate>
                <value>1988-08-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares of Beneficial Interest</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>44794</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>44794</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Revocable Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares reported on this line are owned directly and are subject to vesting.</footnote>
        <footnote id="F2">Shares reported herein are owned by The Security Trust Company, as Trustee of the Equity Residential Supplemental Retirement Plan for the benefit of the Reporting Person.</footnote>
        <footnote id="F3">56,273 share options reported herein will become exercisable on February 7, 2004; 56,273 share options will become exercisable on February 7, 2005; and 56,274 share options will become exercisable on February 7, 2006.</footnote>
        <footnote id="F4">1,333 share options reported herein are currently exercisable; 1,334 share options will become exercisable on March 14, 2003; and 1,333 share options will become exercisable on March 14, 2004.</footnote>
        <footnote id="F5">13,787 share options reported herein will become exercisable on March 14, 2003; 13,787 share options will become exercisable on March 14, 2004; and 13,787 share options will become exercisable on March 14, 2005.</footnote>
        <footnote id="F6">Share options reported on this line will become exercisable in three equal installments on January 27, 2005; January 27, 2006 and January 27, 2007.</footnote>
        <footnote id="F7">OP Units reported herein are indirectly held by Mr. Duncan in the Bruce W. Duncan Revocable Trust under trust agreement dated July 29, 1993.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Bruce W Duncan</signatureName>
        <signatureDate>2004-05-18</signatureDate>
    </ownerSignature>
</ownershipDocument>

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