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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-11-12</periodOfReport>

    <dateOfOriginalSubmission>2015-11-16</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001029800</issuerCik>
        <issuerName>URSTADT BIDDLE PROPERTIES INC</issuerName>
        <issuerTradingSymbol>UBP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001572303</rptOwnerCik>
            <rptOwnerName>Biddle Catherine U</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>53 ELMWOOD RD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH SALEM</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10590</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>524</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.4344</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2701388</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On November 12, 2015, the Trust established under the Urstadt Biddle Properties Inc. Excess Benefit and Deferred Compensation Plan of 2005 (the &quot;Compensation Plan Trust&quot;) purchased 524 shares of Common Stock for the benefit of Willing L. Biddle, the Reporting Person's husband and an officer and a director of the Issuer, at a weighted average price of $17.4344 per share. Upon a request by the Commission, the Issuer, or a shareholder of the Issuer, full information regarding the number of shares purchased and the separate prices at which they were purchased will be provided.</footnote>
        <footnote id="F2">This figure includes 950,000 restricted shares of Common Stock issued to Mr. Biddle and 2,000 restricted shares of Common Stock issued to the Reporting Person pursuant to the Issuer's Amended and Restated Restricted Stock Award Plan.</footnote>
        <footnote id="F3">This amendment is being filed to correctly report the number of shares of Common Stock acquired by the Compensation Plan Trust on November 12, 2015 and allocated to the account of Mr. Biddle (524 shares), which previously was incorrectly reported as 248 shares.</footnote>
        <footnote id="F4">See Exhibit 99.1</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Catherine U. Biddle by Thomas D. Myers as Attorney-in-Fact</signatureName>
        <signatureDate>2016-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
