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

    <documentType>4</documentType><periodOfReport>2003-11-10</periodOfReport>
    <issuer>
        <issuerCik>0000039677</issuerCik>
        <issuerName>AVATAR HOLDINGS INC</issuerName>
        <issuerTradingSymbol>AVTR</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001024348</rptOwnerCik>
            <rptOwnerName>SPEARS WILLIAM G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SPEARS, GRISANTI &amp; BROWN</rptOwnerStreet1>
            <rptOwnerStreet2>45 ROCKEFELLER PLAZA, #1709</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock, $1.00 par value</value></securityTitle><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1823</value></transactionShares><transactionPricePerShare><value>31.80</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>10323</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value>By WGS Profit Sharing Plan</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock, $1.00 par value</value></securityTitle><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1761</value></transactionShares><transactionPricePerShare><value>31.80</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>6761</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By WGS Charitable Remainder Trust</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock, $1.00 par value</value></securityTitle><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>314</value></transactionShares><transactionPricePerShare><value>31.80</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2814</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Family Foundation</value></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock, $1.00 par value</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>19600</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding><nonDerivativeHolding><securityTitle><value>Common Stock, $1.00 par value</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Estate of former wife</value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>7% Convertible Subordinated Notes due 2005</value></securityTitle><conversionOrExercisePrice><value>31.80</value></conversionOrExercisePrice><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionTotalValue><value>58000.00</value></transactionTotalValue><transactionPricePerShare><value>58000.00</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-11-10</value></exerciseDate><expirationDate><value>2005-04-01</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock, $1.00 par value</value></underlyingSecurityTitle><underlyingSecurityShares><value>1823</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value>By WGS Profit Sharing Plan</value></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>7% Convertible Subordinated Notes due 2005</value></securityTitle><conversionOrExercisePrice><value>31.80</value></conversionOrExercisePrice><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionTotalValue><value>56000.00</value></transactionTotalValue><transactionPricePerShare><value>56000.00</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-11-10</value></exerciseDate><expirationDate><value>2003-04-01</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock, $1.00 par value</value></underlyingSecurityTitle><underlyingSecurityShares><value>1761</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By WGS Charitable Remainder Trust</value></natureOfOwnership></ownershipNature></derivativeTransaction><derivativeTransaction><securityTitle><value>7% Convertible Subordinated Notes due 2005</value></securityTitle><conversionOrExercisePrice><value>31.80</value></conversionOrExercisePrice><transactionDate><value>2003-11-10</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>C</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionTotalValue><value>10000.00</value></transactionTotalValue><transactionPricePerShare><value>10000.00</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-11-10</value></exerciseDate><expirationDate><value>2003-04-01</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock, $1.00 par value</value></underlyingSecurityTitle><underlyingSecurityShares><value>314</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>By Family Foundation</value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes/><remarks/><ownerSignature><signatureName>William G. Spears</signatureName><signatureDate>2003-11-12</signatureDate></ownerSignature></ownershipDocument>

