American Capital 10-Q Quarterly report

Exhibit 32

Certification of CEO and CFO Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report on Form 10-Q of American Capital Strategies, Ltd. (the “Company”), for the fiscal quarter ended March 31, 2007, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), Malon Wilkus as Chief Executive Officer of the Company, and John R. Erickson, as Chief Financial Officer of the Company, each hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of his knowledge, respectively, that:

1. The Report fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ MALON WILKUS

Name:     Malon Wilkus

Title:       Chairman of the Board,

                    Chief Executive Officer and President

Date:       May 10, 2007

/s/ JOHN R. ERICKSON

Name:     John R. Erickson

Title:       Executive Vice President and

                    Chief Financial Officer

Date:        May 10, 2007

The certification accompanies the Report pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the Sarbanes-Oxley Act of 2002, be deemed filed by the Company for purposes of Section 18 of the Securities Exchange Act of 1934, as amended. A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.