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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000027613</issuerCik>
        <issuerName>DECORATOR INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>DII</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001105838</rptOwnerCik>
            <rptOwnerName>ROBOTTI ROBERT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $0.20 Per Share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>180</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.6</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>555418</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This amount includes 333,335 shares of the Common Stock, directly owned by the discretionary accounts of Robotti &amp; Company, LLC (&quot;Robotti &amp; Company&quot;), a broker-dealer registered under Section 15 of the Securities Exchange Act of 1934 (&quot;Exchange Act&quot;), as amended, and by the advisory clients of Robotti &amp; Company Advisors, LLC (&quot;Robotti &amp; Company Advisors&quot;) registered under the Investment Advisors Act of 1940 and beneficially owned by its discretionary brokerage customers and advisory clients.</footnote>
        <footnote id="F2">This amount includes 217,318 shares of the Common Stock directly owned by The Ravenswood Investment Company, L.P. (&quot;RIC&quot;) and beneficially owned by its partners.</footnote>
        <footnote id="F3">This amount includes 4,765 shares of the Common Stock directly owned by Suzanne and Robert Robotti Foundation, Inc. (&quot;Robotti Foundation&quot;), a Delaware corporation.</footnote>
        <footnote id="F4">Mr. Robotti is deemed to beneficially own (solely for the purpose of Rule 16a-1(a)(2) under the Exchange Act) the securities set forth in footnotes (1), (2) and (3) above through his proportionate ownership of Robotti &amp; Company, Incorporated, a New York corporation and the parent holding company of Robotti &amp; Company and Robotti &amp; Company Advisors, by virtue of the investment discretion Robotti and Company and Robotti &amp; Company Advisors have over the accounts of its brokerage customers and advisory clients, and as managing member of Ravenswood Management Company, L.L.C. which serves as the general partner of RIC, and as a Director of Robotti Foundation.  Mr. Robotti disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert E. Robotti</signatureName>
        <signatureDate>2005-05-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
