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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-10-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001320760</issuerCik>
        <issuerName>Fortress International Group, Inc.</issuerName>
        <issuerTradingSymbol>Figi</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001166432</rptOwnerCik>
            <rptOwnerName>SONKIN PAUL D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001101758</rptOwnerCik>
            <rptOwnerName>HUMMINGBIRD VALUE FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001243818</rptOwnerCik>
            <rptOwnerName>HUMMINGBIRD MICROCAP VALUE FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001276582</rptOwnerCik>
            <rptOwnerName>HUMMINGBIRD CONCENTRATED FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001333738</rptOwnerCik>
            <rptOwnerName>TARSIER NANOCAP VALUE FUND, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HUMMINGBIRD MANAGEMENT, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001164073</rptOwnerCik>
            <rptOwnerName>HUMMINGBIRD MANAGEMENT LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001249876</rptOwnerCik>
            <rptOwnerName>HUMMINGBIRD CAPITAL LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 E. 57TH STREET, 8TH FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>see footnote #1</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2008-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>250</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.064</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>396233</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>400</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.031</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>396633</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F5"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1200</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.015</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>721644</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F7"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                    <footnoteId id="F8"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.088</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>722144</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F9"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>800</value>
                    <footnoteId id="F10"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.156</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>722944</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F11"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                    <footnoteId id="F12"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.127</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>723444</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F13"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock $.0001 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1500</value>
                    <footnoteId id="F14"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.0839</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F15"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is filed jointly by Paul D. Sonkin, The Hummingbird Value Fund, L.P. (&quot;HVF&quot;), The Hummingbird Microcap Value Fund, L.P.(&quot;Microcap&quot;),The Hummingbird Concentrated Fund, L.P. (&quot;Concentrated&quot;), The Tarsier Nanocap Value Fund, L.P. (&quot;Tarsier&quot;),Hummingbird Capital, LLC, and Hummingbird Management, LLC. Paul D. Sonkin is the Managing Member of (a) Hummingbird Capital, LLC, the general partner of HVF, Microcap, Concentrated, and Tarsier and (b) Hummingbird Management, LLC, the investment manager to HVF, Microcap, Concentrated and Tarsier. Accordingly, each of Paul D. Sonkin, Hummingbird Capital, LLC, and Hummingbird Management, LLC may be deemed to beneficially own the securities owned by HVF, Microcap, Concentrated, and Tarsier reported herein. The Reporting Persons are members of a Section 13(d) group that owns more than 10% of the Issuer's outstanding Common Stock.</footnote>
        <footnote id="F2">Acquired by The Hummingbird Microcap Value Fund, LP.</footnote>
        <footnote id="F3">Owned directly by The Hummingbird Microcap Value Fund, L.P., and indirectly by Paul D. Sonkin, Hummingbird Capital, LLC, and Hummingbird Management, LLC, each of which disclaims beneficial ownership of the securities owned by The Hummingbird Value Microcap Fund, L.P., except to the extent that each such party has an interest, if any, in The Hummingbird Microcap Value Fund, L.P.</footnote>
        <footnote id="F4">See footnote #2.</footnote>
        <footnote id="F5">See footnote #3.</footnote>
        <footnote id="F6">Acquired by The Hummingbird Concentrated Fund, LP.</footnote>
        <footnote id="F7">Owned directly by The Hummingbird Concentrated Fund, L.P., and indirectly by Paul D. Sonkin, Hummingbird Capital, LLC,  and Hummingbird Management, LLC, each of which disclaims beneficial ownership of the securities owned by The Hummingbird Concentrated Fund, L.P., except to the extent that each such party has an interest, if any, in The Hummingbird Concentrated Fund, L.P.</footnote>
        <footnote id="F8">See footnote #6.</footnote>
        <footnote id="F9">See footnote #7.</footnote>
        <footnote id="F10">See footnote #6.</footnote>
        <footnote id="F11">See footnote #7.</footnote>
        <footnote id="F12">See footnote #6.</footnote>
        <footnote id="F13">See footnote #7.</footnote>
        <footnote id="F14">Acquired by The Tarsier Nanocap Value Fund, LP.</footnote>
        <footnote id="F15">Owned directly by The Tarsier Nanocap Value Fund, LP., and indirectly by Paul D. Sonkin, Hummingbird Capital, LLC, and Hummingbird Management, LLC, each of which disclaims beneficial ownership of the securities owned by The Tarsier Nanocap Value Fund, L.P., except to the extent that each such party has an interest, if any, in The Tarsier Nanocap Value Fund, L.P.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Paul Sonkin</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hummingbird Value Fund, LP</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hummingbird Microcap Value Fund, LP</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hummingbird Concentrated Fund, LP</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Tarsier Nanocap Value Fund, LP</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hummingbird Management, LLC</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Hummingbird Capital, LLC</signatureName>
        <signatureDate>2008-12-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
