<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2004-01-13</periodOfReport>
    <issuer>
        <issuerCik>0000740260</issuerCik>
        <issuerName>VENTAS INC</issuerName>
        <issuerTradingSymbol>VTR</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001215188</rptOwnerCik>
            <rptOwnerName>CAFARO DEBRA A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10350 ORMSBY PARK PLACE, SUITE 300</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOUISVILLE,</rptOwnerCity>
            <rptOwnerState>KY</rptOwnerState>
            <rptOwnerZipCode>40223</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Chairman, President and CEO</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-13</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>F</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>11834</value><footnoteId id="F1"/></transactionShares><transactionPricePerShare><value>23.00</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>744642</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Represents share withholding under the Company's 2000 Incentive Compensation Plan to pay tax withholding on the vesting of Restricted Stock previously granted to Reporting Person.</footnote></footnotes><remarks/><ownerSignature><signatureName>Debra A. Cafaro</signatureName><signatureDate>2004-01-14</signatureDate></ownerSignature></ownershipDocument>
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X0201
4
2004-01-13
0000740260
VENTAS INC
VTR
0001215188
CAFARO DEBRA A
10350 ORMSBY PARK PLACE, SUITE 300
LOUISVILLE,
KY
40223
1
1
0
0
Chairman, President and CEO
Common Stock
2004-01-13
4
F
0
11834
23.00
D
744642
D
Represents share withholding under the Company's 2000 Incentive Compensation Plan to pay tax withholding on the vesting of Restricted Stock previously granted to Reporting Person.
Debra A. Cafaro
2004-01-14