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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2014-04-25</periodOfReport>

    <dateOfOriginalSubmission>2014-05-02</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000040417</issuerCik>
        <issuerName>GENERAL AMERICAN INVESTORS CO INC</issuerName>
        <issuerTradingSymbol>GAM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001264679</rptOwnerCik>
            <rptOwnerName>TRUST FBO ALTSCHUL EMILY H UW ALTSCHUL HG</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OVERBROOK MANAGEMENT CORP</rptOwnerStreet1>
            <rptOwnerStreet2>122 EAST 42ND STREET SUITE 2500</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10168-2500</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Chairman</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-04-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>36.4369</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10246</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>5.95% Preferred Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reversal of sales transaction reported for the wrong Trust account. The sale went against Trust FBO Emily H. Altschul UW Helen G. Altschul, it should have been reported under Trust FBO Emily H. Altschul UAD 12/15/72.</footnote>
        <footnote id="F2">Shares added back to trust account balance to reverse the incorrect reporting of sales transaction on this account.</footnote>
        <footnote id="F3">Price stated is price of original sale.</footnote>
    </footnotes>

    <remarks>Following sales transaction were made on 5/19/2014 &amp; 5/20/2014 for 788 shares and 212 shares respectively. The ending balance of shares on 5/20/2014 should be 9,426.</remarks>

    <ownerSignature>
        <signatureName>/s/ Spencer Davidson, Trustee, Trust FBO Emily H. Altschul, U/W H.G. Altschul</signatureName>
        <signatureDate>2015-02-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
