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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-04</periodOfReport>

    <issuer>
        <issuerCik>0000027904</issuerCik>
        <issuerName>DELTA AIR LINES INC /DE/</issuerName>
        <issuerTradingSymbol>DAL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001225114</rptOwnerCik>
            <rptOwnerName>FORET MICKEY P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DELTA AIR LINES, INC., DEPT. 981</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 20574</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA,</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30320</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</value>
            </securityTitle>
            <transactionDate>
                <value>2010-01-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>93</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35166</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Aviation Consultants, LLC</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24728</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares of Delta common stock were distributed by Delta in accordance with the First Amended Joint and Consolidated Plan of Reorganization under Chapter 11 of the Bankruptcy Code (the &quot;Plan of Reorganization&quot;) for Northwest Airlines Corporation (&quot;Northwest&quot;) and certain of its affiliated entities (collectively, the &quot;Debtors&quot;) with respect to a pre-petition unsecured claim held by Aviation Consultants, LLC, an affiliate of Mr. Foret.  Northwest became a subsidiary of Delta on October 29, 2008.  Pursuant to the Plan of Reorganization, Aviation Consultants, LLC has in the past received shares of Northwest common stock.  These shares were converted to Delta common stock upon consummation of the merger of Northwest and Delta.  Aviation Consultants, LLC may in the future receive additional shares of Delta common stock with respect to this same claim as all unsecured claims held by creditors of the Debtors continue to be reconciled.</footnote>
        <footnote id="F2">Mr. Foret is the sole member of Aviation Consultants, LLC.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jan M. Davidson as attorney-in-fact for Mickey P. Foret</signatureName>
        <signatureDate>2010-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
