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

In connection with the Annual Report of Zoltek Companies, Inc. (the “Company”) on Form 10-K for the period ending September 30, 2009 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Zsolt Rumy, Chief Executive Officer of the Company, certify, 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 my knowledge and belief, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) 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.

Date: November 30, 2009	By:	/s/ ZSOLT RUMY
		Zsolt Rumy
		Chief Executive Officer