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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-06-23</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001423535</rptOwnerCik>
            <rptOwnerName>DeArmas Francisco</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>228 ST. CHARLES AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW ORLEANS</rptOwnerCity>
            <rptOwnerState>LA</rptOwnerState>
            <rptOwnerZipCode>70130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock no par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common stock no par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1233.025</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held for the reporting person in the Company's 401(k) plan as reported by the Trustee on 6/30/2009.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Nonqual opt</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.77</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2011-06-23</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Comm stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6050</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6050</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted stock units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-06-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Comm stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options granted under the Company's Long Term Incentive Plan in accordance with Rule 16b-3(d).</footnote>
        <footnote id="F2">Each restricted stock unit represents a contingent right to receive one share of Whitney Holding Corporation common stock.</footnote>
        <footnote id="F3">The restricted stock units vest (become non-forfeitable) on the third anniversary of the grant date.  Vested restricted stock units convert to shares of common stock on the later of (i) within 30 days following the vesting date or (ii) the earliest permissible date such units may  convert to shares of common stock as a result of the issuer's receipt of financial assistance under the Department of the Treasury's Troubled Asset Relief Program.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Patricia K. Loupe, Sr. Assistant Corporate Secretary for Whitney Holding Corporation and attorney-in-fact</signatureName>
        <signatureDate>2009-07-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0303
4
2009-06-23
0000106926
WHITNEY HOLDING CORP
WTNY
0001423535
DeArmas Francisco
228 ST. CHARLES AVENUE
NEW ORLEANS
LA
70130
0
1
0
0
Executive Vice President
Common stock no par value
1000
D
Common stock no par value
1233.025
I
Held for the reporting person in the Company's 401(k) plan as reported by the Trustee on 6/30/2009.
Nonqual opt
18.77
2011-06-23
2018-06-23
Comm stock
6050
6050
D
Restricted stock units
2009-06-23
4
A
0
7500
0
A
Comm stock
7500
7500
D
Options granted under the Company's Long Term Incentive Plan in accordance with Rule 16b-3(d).
Each restricted stock unit represents a contingent right to receive one share of Whitney Holding Corporation common stock.
The restricted stock units vest (become non-forfeitable) on the third anniversary of the grant date.  Vested restricted stock units convert to shares of common stock on the later of (i) within 30 days following the vesting date or (ii) the earliest permissible date such units may  convert to shares of common stock as a result of the issuer's receipt of financial assistance under the Department of the Treasury's Troubled Asset Relief Program.
Patricia K. Loupe, Sr. Assistant Corporate Secretary for Whitney Holding Corporation and attorney-in-fact
2009-07-01