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

    <schemaVersion>X0304</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-02-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000767884</issuerCik>
        <issuerName>Ceres, Inc.</issuerName>
        <issuerTradingSymbol>CERE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001332737</rptOwnerCik>
            <rptOwnerName>Warburg Pincus Private Equity IX, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark **</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001342445</rptOwnerCik>
            <rptOwnerName>Warburg Pincus IX LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark **</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001322709</rptOwnerCik>
            <rptOwnerName>Warburg Pincus Partners LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark **</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000929408</rptOwnerCik>
            <rptOwnerName>WARBURG PINCUS &amp; CO.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>NEW YORK</rptOwnerStreet2>
            <rptOwnerCity>NY</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>100173147</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See Remark **</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001162870</rptOwnerCik>
            <rptOwnerName>WARBURG PINCUS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 LEXINGTON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001239318</rptOwnerCik>
            <rptOwnerName>KAYE CHARLES R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220638</rptOwnerCik>
            <rptOwnerName>Landy Joseph P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>450 LEXINGTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Convertible Subordinated Promissory Note</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>10.40</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2012-02-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>1592400</value>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>153115</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>1592400</value>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Convertible Subordinated Promissory Note (the &quot;Convertible Note&quot;) of Ceres, Inc., a Delaware corporation (the &quot;Issuer&quot;), is held by Warburg Pincus Private Equity IX, L.P., a Delaware limited partnership (&quot;WP IX&quot;), and is automatically convertible, subject to the terms and conditions set forth therein, into the Issuer's common stock, par value $0.01 (the &quot;Common Stock&quot;), upon the consummation of a qualified initial public offering (&quot;IPO&quot;) of the Common Stock at a price per share equal to 20% discount from the public offering price.  Since the public offering price was $13.00, the price per share is $10.40. The offering price was determined on February 21, 2012, at which time the Convertible Note became a derivative security.</footnote>
        <footnote id="F2">Warburg Pincus IX LLC, a New York limited liability company (&quot;WP IX GP&quot;), is the general partner of WP IX.  Warburg Pincus Partners LLC, a New York limited liability company (&quot;WP Partners&quot;), is the sole member of WP IX GP.  Warburg Pincus &amp; Co., a New York general partnership (&quot;WP&quot;), is the managing member of WP Partners.  Warburg Pincus LLC, a New York limited liability company (&quot;WP LLC&quot;), manages WP IX.  Charles R. Kaye and Joseph P. Landy are the Managing General Partners of WP and the Co-Presidents and Managing Members of WP LLC and may be deemed to control WP IX, WP IX GP, WP Partners, WP and WP LLC (together with Messrs. Kaye and Landy, the &quot;Warburg Pincus Reporting Persons&quot;).</footnote>
        <footnote id="F3">By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;), WP IX GP, WP Partners, WP, WP LLC and Messrs. Kaye and Landy may be deemed to be beneficial owners of the Convertible Note of the Issuer held by WP IX.  Pursuant to Rule 16a-1(a)(4) of the Exchange Act, each of the Warburg Pincus Reporting Persons, other than WP IX, herein states that this Form 4 shall not be deemed an admission that it or he is the beneficial owner of any of the Common Stock or any other securities of the Issuer reported in this Form 4.  Each of the Warburg Pincus Reporting Persons disclaims beneficial ownership of such securities, except to the extent it or he has a pecuniary interest in such securities.</footnote>
    </footnotes>

    <remarks>*   Powers of Attorney given by Messrs. Kaye and Landy were previously filed with the U.S. Securities and Exchange Commission on March 2, 2006 as exhibits to the Schedule 13D filed by Building Products, LLC with respect to Builders FirstSource, Inc.  **  Solely for the purposes of Section 16 of the Exchange Act, each of WP IX, WP IX GP, WP Partners and WP may be deemed a director-by-deputization.  Although after the completion of the IPO the Warburg Pincus Reporting Persons will not have a contractual right to a seat on the board of directors of the Issuer, Mr.  Krieger is an elected director of the board of directors of the Issuer, and is also a Partner of WP and a Member and Managing Director of WP LLC. *** Information with respect to each of the Warburg Pincus Reporting Persons is given solely by such Warburg Pincus Reporting Person, and no Warburg Pincus Reporting Person has responsibility for the accuracy or completeness of information supplied by another Warburg Pincus Reporting Person.</remarks>

    <ownerSignature>
        <signatureName>_____________________, Partner of Warburg Pincus &amp; Co., the managing member of Warburg Pincus Partners LLC, the sole member of Warburg Pincus IX LLC, the general partner of Warburg Pincus Private Equity IX, L.P.</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>_____________________, Partner of Warburg Pincus &amp; Co., the managing member of Warburg Pincus Partners LLC, the sole member of Warburg Pincus IX LLC</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>_____________________, Partner of Warburg Pincus &amp; Co., the managing member of Warburg Pincus Partners LLC</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>______________________, Partner of Warburg Pincus &amp; Co.</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>________________, Managing Director of Warburg Pincus LLC</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>_____________________, as attorney-in-fact for Charles R. Kaye *</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>_____________________, as attorney-in-fact for Joseph P. Landy *</signatureName>
        <signatureDate>2012-02-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
