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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-01-17</periodOfReport>

    <issuer>
        <issuerCik>0000098246</issuerCik>
        <issuerName>TIFFANY &amp; CO</issuerName>
        <issuerTradingSymbol>TIF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001329399</rptOwnerCik>
            <rptOwnerName>Iglesias Henry</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>TIFFANY &amp; CO.</rptOwnerStreet1>
            <rptOwnerStreet2>727 FIFTH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP-CONTRLR principal acctg off</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock $.01 OPar</value>
            </securityTitle>
            <transactionDate>
                <value>2008-01-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1332</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9146.93</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $.01 Par</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>51.6122</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>ESOP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock $.01 Par</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>78.7647</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>ESPP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance-based Restricted Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-01-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1992</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1992</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1992</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Given for no consideration.</footnote>
        <footnote id="F2">7,581 shares in the total are shares underlying RSUs.</footnote>
        <footnote id="F3">The performance-based restricted stock units convert to the company's common stock on a one-for-one basis.</footnote>
        <footnote id="F4">Granted pursuant to the Tiffany &amp; Co. 2005 Employee Incentive Plan, which complies with Rule 16(b)-3.</footnote>
        <footnote id="F5">All or a percentage of the units will be eligible for conversion to common stock if issuer satisfies financial performance criteria for the fiscal year ending January 31, 2009.  Eligibility for conversion will be determined on the basis of audited financial statements released for such fiscal year. Twenty-five percent of units determined eligible will vest three business days after the release of such financial statements (the &quot;Determination Date&quot;) if the reporting person then remains employed; additional portions of 25%  each will vest on each of the next three anniversaries of the Determination Date if the reporting person remains employed.  Performance-based restricted stock units not eligible for conversion will be canceled.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Patrick B. Dorsey, Attorney-in-Fact</signatureName>
        <signatureDate>2008-01-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2008-01-17
0000098246
TIFFANY & CO
TIF
0001329399
Iglesias Henry
TIFFANY & CO.
727 FIFTH AVENUE
NEW YORK
NY
10022
0
1
0
0
VP-CONTRLR principal acctg off
Common Stock $.01 OPar
2008-01-17
4
A
0
1332
0
A
9146.93
D
Common Stock $.01 Par
51.6122
I
ESOP
Common Stock $.01 Par
78.7647
I
ESPP
Performance-based Restricted Stock Unit
2007-01-18
4
A
0
1992
0
A
Common Stock
1992
1992
D
Given for no consideration.
7,581 shares in the total are shares underlying RSUs.
The performance-based restricted stock units convert to the company's common stock on a one-for-one basis.
Granted pursuant to the Tiffany & Co. 2005 Employee Incentive Plan, which complies with Rule 16(b)-3.
All or a percentage of the units will be eligible for conversion to common stock if issuer satisfies financial performance criteria for the fiscal year ending January 31, 2009.  Eligibility for conversion will be determined on the basis of audited financial statements released for such fiscal year. Twenty-five percent of units determined eligible will vest three business days after the release of such financial statements (the "Determination Date") if the reporting person then remains employed; additional portions of 25%  each will vest on each of the next three anniversaries of the Determination Date if the reporting person remains employed.  Performance-based restricted stock units not eligible for conversion will be canceled.
/s/ Patrick B. Dorsey, Attorney-in-Fact
2008-01-22