<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-07-09</periodOfReport>
    <issuer>
        <issuerCik>0000922864</issuerCik>
        <issuerName>APARTMENT INVESTMENT &amp; MANAGEMENT CO</issuerName>
        <issuerTradingSymbol>AIV</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001035261</rptOwnerCik>
            <rptOwnerName>ELLWOOD RICHARD S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Class A Common Stock</value></securityTitle><transactionDate><value>2003-07-09</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1500</value></transactionShares><transactionValue><value>27.25</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11325</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value><footnoteId id="F1"/></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeSecurity><derivativeSecurity><securityTitle><value>Option (right to buy)</value></securityTitle><conversionOrExercisePrice><value>27.25</value></conversionOrExercisePrice><transactionDate><value>2003-07-09</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1500</value></transactionShares><transactionValue><value>27.25</value></transactionValue><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>1998-04-24</value></exerciseDate><expirationDate><value>2007-04-24</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Class A Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1500</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1500</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">In addition to the 11,325 shares held directly by Mr. Ellwood, Mr. Ellwood holds indirectly 8,200 shares.  Of those 8,200 shares held indirectly by Mr. Ellwood, 7,500 shares are held in an IRA belonging to Mr. Ellwood and 500 shares are held by R.S. Ellwood &amp; Co., Inc., an entity of which Mr. Ellwood is the sole shareholder.  The remaining 200 shares held indirectly by Mr. Ellwood are held by a charitable trust for which shares Mr. Ellwood disclaims beneficial ownership.  In addition, Mr. Ellwood's wife holds 1,200 shares, for which shares Mr. Ellwood disclaims beneficial ownership.</footnote></footnotes><ownerSignature><signatureName>Richard S. Ellwood</signatureName><signatureDate>2003-07-10</signatureDate></ownerSignature></ownershipDocument>

