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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-06-04</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000106926</issuerCik>
        <issuerName>WHITNEY HOLDING CORP</issuerName>
        <issuerTradingSymbol>WTNY</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001479255</rptOwnerCik>
            <rptOwnerName>Fowler Hardy B.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>909 POYDRAS STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2900</rptOwnerStreet2>
            <rptOwnerCity>NEW ORLEANS</rptOwnerCity>
            <rptOwnerState>LA</rptOwnerState>
            <rptOwnerZipCode>70112</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 no par value</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>19349</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock no par value</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2466</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Mr. Fowler's wife in her IRA.  Mr. Fowler disclaims beneficial ownership fo these shares.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Disposed of pursuant to merger agreement between the Company and Hancock Holding Company (&quot;Hancock&quot;).  For each share of Company common stock, the reporting person received .418 of a share of Hancock common stock having a market value of $32.04 per share on the effective date of the merger.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Patricia K. Loupe, attorney-in-fact and agent in fact for Whitney Holding Corporation</signatureName>
        <signatureDate>2011-06-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0303
4
2011-06-04
1
0000106926
WHITNEY HOLDING CORP
WTNY
0001479255
Fowler Hardy B.
909 POYDRAS STREET
SUITE 2900
NEW ORLEANS
LA
70112
1
0
0
0
Common stock no par value
2011-06-04
4
D
0
19349
D
0
D
Common stock no par value
2011-06-04
4
D
0
2466
D
0
I
Held by Mr. Fowler's wife in her IRA.  Mr. Fowler disclaims beneficial ownership fo these shares.
Disposed of pursuant to merger agreement between the Company and Hancock Holding Company ("Hancock").  For each share of Company common stock, the reporting person received .418 of a share of Hancock common stock having a market value of $32.04 per share on the effective date of the merger.
/s/ Patricia K. Loupe, attorney-in-fact and agent in fact for Whitney Holding Corporation
2011-06-07