<SEC-DOCUMENT>0001728564-18-000005.txt : 20180129
<SEC-HEADER>0001728564-18-000005.hdr.sgml : 20180129
<ACCEPTANCE-DATETIME>20180129094535
ACCESSION NUMBER:		0001728564-18-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180125
FILED AS OF DATE:		20180129
DATE AS OF CHANGE:		20180129

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kent Thomas M
		CENTRAL INDEX KEY:			0001728564

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-04889
		FILM NUMBER:		18553729

	MAIL ADDRESS:	
		STREET 1:		19 ALBEE DRIVE
		CITY:			BRAINTREE
		STATE:			MA
		ZIP:			02184

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TEKLA HEALTHCARE INVESTORS
		CENTRAL INDEX KEY:			0000805267
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 0000 [0000]
		IRS NUMBER:				046564285
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		100 FEDERAL STREET
		STREET 2:		19TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
		BUSINESS PHONE:		6177728515

	MAIL ADDRESS:	
		STREET 1:		100 FEDERAL STREET
		STREET 2:		19TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	H&Q HEALTHCARE INVESTORS
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-01-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000805267</issuerCik>
        <issuerName>TEKLA HEALTHCARE INVESTORS</issuerName>
        <issuerTradingSymbol>HQH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001728564</rptOwnerCik>
            <rptOwnerName>Kent Thomas M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>19 ALBEE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BRAINTREE</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02184</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Shares of Beneficial Interest</value>
            </securityTitle>
            <transactionDate>
                <value>2018-01-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>24.1862</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1100</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Thomas M. Kent</signatureName>
        <signatureDate>2018-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
