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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-07-15</periodOfReport>

    <issuer>
        <issuerCik>0001036960</issuerCik>
        <issuerName>FAIRCHILD SEMICONDUCTOR INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>NYSE: FCS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001262608</rptOwnerCik>
            <rptOwnerName>CONRAD ROBERT J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>FAIRCHILD SEMICONDUCTOR INTERNATIONAL</rptOwnerStreet1>
            <rptOwnerStreet2>82 RUNNING HILL ROAD</rptOwnerStreet2>
            <rptOwnerCity>SOUTH PORTLAND</rptOwnerCity>
            <rptOwnerState>ME</rptOwnerState>
            <rptOwnerZipCode>04106</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15.91</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-07-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-07-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-07-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6667</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6667</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6667</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Grant becomes exercisable in 25% increments on each of the first four anniversaries of the date of the grant, or earlier upon certain events.</footnote>
        <footnote id="F2">This footnote is inserted only to meet technical requirements of the SEC.  Deferred Stock Units cannot be assigned an exercise price.</footnote>
        <footnote id="F3">Reported number of Performance Units acquired is based on company attaining 100% EBIT Target.  If company achieves EBIT Target of 200% or higher, reporting person will receive two times (2x) the reported number.  If company fails to achieve 50% EBIT Target, the reporting person will receive no Performance Units.  If company's EBIT performance falls between 50% and 200% EBIT Targets, the reporting person will receive a reduced number of shares determined according to linear interpolation.</footnote>
        <footnote id="F4">Performance Units vest in the following increments, or earlier upon certain events:  33% on July 15, 2006; 33% on February 15, 2007 and 34% on February 15, 2008.  Performance Units have no expiration date.  Vested Performance Units result in delivery of the underlying shares of common stock, and all the Performance Units are forfeited if the company fails to achieve the 50% EBIT Target.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Paul D. Delva (Attorney-in-fact)</signatureName>
        <signatureDate>2005-07-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
