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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Kc4g7E1foDaHM2+yOEHrR5bXungzRK49r/LCJt9k9KLhNYQIRMK635lALQidufO0
 kVfSEku7YnhMARU4Ly4+1A==

<SEC-DOCUMENT>0001209191-08-031950.txt : 20080521
<SEC-HEADER>0001209191-08-031950.hdr.sgml : 20080521
<ACCEPTANCE-DATETIME>20080521101335
ACCESSION NUMBER:		0001209191-08-031950
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080519
FILED AS OF DATE:		20080521
DATE AS OF CHANGE:		20080521

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FNB CORP/FL/
		CENTRAL INDEX KEY:			0000037808
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				251255406
		STATE OF INCORPORATION:			FL
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		F.N.B. CORPORATION
		STREET 2:		ONE F.N.B. BOULEVARD
		CITY:			HERMITAGE
		STATE:			PA
		ZIP:			16148
		BUSINESS PHONE:		724-981-6000

	MAIL ADDRESS:	
		STREET 1:		F.N.B. CORPORATION
		STREET 2:		ONE F.N.B. BOULEVARD
		CITY:			HERMITAGE
		STATE:			PA
		ZIP:			16148

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FNB CORP/PA
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CITIZENS BUDGET CO
		DATE OF NAME CHANGE:	19750909

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NEW ROBERT V JR
		CENTRAL INDEX KEY:			0001220828

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31940
		FILM NUMBER:		08850696

	BUSINESS ADDRESS:	
		STREET 1:		3121 BUFFALO SPEEDWAY, #3308
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77098
		BUSINESS PHONE:		7134355075

	MAIL ADDRESS:	
		STREET 1:		5718 WESTHEIMER
		STREET 2:		SUITE 600
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77057
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-05-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000037808</issuerCik>
        <issuerName>FNB CORP/FL/</issuerName>
        <issuerTradingSymbol>FNB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220828</rptOwnerCik>
            <rptOwnerName>NEW ROBERT V JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2165 OAK HAVEN COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HERMITAGE</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>16148</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO Elect</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.12</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18119</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/Robert V. New, Jr.</signatureName>
        <signatureDate>2008-05-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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