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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-01-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000003545</issuerCik>
        <issuerName>ALICO INC</issuerName>
        <issuerTradingSymbol>alco</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001591417</rptOwnerCik>
            <rptOwnerName>Fishman Benjamin D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ARLON GROUP, 277 PARK AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10172</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Alico, Inc., Common Stock, Par Value $1.00</value>
            </securityTitle>
            <transactionDate>
                <value>2019-01-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>946</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19698</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were issued under the Stock Incentive Plan of 2015.</footnote>
        <footnote id="F2">The shares of the Company's Common Stock being reported in this Form 4 were issued to Benjamin D. Fishman, an employee of an affiliate of Arlon Food and Agriculture Advisors, LLC, as nominee on behalf of Arlon Food and Agriculture Advisors LLC and Arlon Valencia Holdings LLC (collectively, &quot;Arlon&quot;).  Mr. Fishman is required to transfer such shares to Arlon Valencia Holdings LLC.  Mr. Fishman is serving as a director of the Company on behalf of Arlon and received the shares of the Company's Common Stock, as nominee on Behalf of Arlon, in connection with such service on the Company's board of directors.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Benjamin Fishman</signatureName>
        <signatureDate>2019-01-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
