FS KKR Capital (FSK) 10-Q 2010 Q2 Quarterly report

Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Michael C. Forman, the chief executive officer of FS Investment Corporation (the “Company”), hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge:

• the Form 10-Q of the Company for the three months ended June 30, 2010 as filed with the Securities and Exchange Commission on the date hereof (the “Form 10-Q”), fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or 78o(d)); and

• the information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company.

Dated: August 16, 2010

/s/    MICHAEL C. FORMAN        

Michael C. Forman

Chief Executive Officer