<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-05-15</periodOfReport>

    <issuer>
        <issuerCik>0000103884</issuerCik>
        <issuerName>ALEXANDERS J CORP</issuerName>
        <issuerTradingSymbol>JAX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001252842</rptOwnerCik>
            <rptOwnerName>LEWIS R GREGORY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3401 WEST END AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 260</rptOwnerStreet2>
            <rptOwnerCity>NASHVILLE</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>37203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President-Finance &amp; Sec.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.09</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-05-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-05-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option is scheduled to vest in four equal installments on May 15, 2008, 2009, 2010 and 2011.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>R. Gregory Lewis</signatureName>
        <signatureDate>2007-05-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2007-05-15
0000103884
ALEXANDERS J CORP
JAX
0001252842
LEWIS R GREGORY
3401 WEST END AVENUE
SUITE 260
NASHVILLE
TN
37203
0
1
0
0
Vice President-Finance & Sec.
Employee Stock Option (Right to Buy)
13.09
2007-05-15
4
A
0
25000
0
A
2014-05-15
Common Stock
25000
25000
D
The option is scheduled to vest in four equal installments on May 15, 2008, 2009, 2010 and 2011.
R. Gregory Lewis
2007-05-17