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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-12-31</periodOfReport>

    <issuer>
        <issuerCik>0000006951</issuerCik>
        <issuerName>APPLIED MATERIALS INC /DE</issuerName>
        <issuerTradingSymbol>AMAT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001284885</rptOwnerCik>
            <rptOwnerName>CHEN XUN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O APPLIED MATERIALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 58039, 3050 BOWERS AV, M/S 1268</rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>181</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30566</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents number of restricted stock units automatically acquired based on a value of $61.04 per share, the closing price of Applied Materials, Inc. (&quot;Applied&quot;) common stock on December 31, 2019, in a transaction exempt under Rule 16b-3(d). This automatic acquisition resulted from dividends accrued on vested restricted stock units that, pursuant to Dr. Chen's election to defer, will be converted on a one-for-one basis into shares of Applied common stock and paid to him on the date of his termination of service from the Applied Board of Directors.</footnote>
        <footnote id="F2">Number of shares includes: (a) 14,286 restricted stock units previously reported that have vested and which, pursuant to Dr. Chen's election to defer, will be converted on a one-for-one basis into shares of Applied common stock and paid to him on the date of his termination of service from the Applied Board of Directors and (b) 5,988 restricted stock units previously reported that are scheduled to vest in March 2020 (subject to continued service as a director through the vesting date).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ To-Anh Nguyen, Attorney-in-Fact</signatureName>
        <signatureDate>2020-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
