<PAGE>

                                 UNITED STATES
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549


                                  FORM 10-K/A
                               (Amendment No. 1)



                 Annual Report Pursuant to Section 13 or 15(d)
                    of the Securities Exchange Act of 1934

For the fiscal year ended September 30, 2006      Commission File Number 0-20600


                            ZOLTEK COMPANIES, INC.
            (Exact name of registrant as specified in its charter)


                Missouri                                43-1311101
     (State or other jurisdiction of        (I.R.S. Employer Identification No.)
     incorporation or organization)


 3101 McKelvey Road, St. Louis, Missouri                     63044
(Address of principal executive offices)                  (Zip Code)


Registrant's telephone number, including area code: (314) 291-5110

Securities registered pursuant to Section 12(b) of the Act: None

Securities registered pursuant to Section 12(g) of the Act: Common Stock,
                                                            par value $.01
                                                            (Title of class)


         Indicate by check mark if the registrant is a well-known seasoned
issuer, as defined in Rule 405 of the Securities Act.   Yes   .  No  X .
                                                           ---      ---

         Indicate by check mark if the registrant is not required to file
reports pursuant to Section 13 or Section 15(d) of the Act.    Yes   .  No  X .
                                                                  ---      ---

         Indicate by check mark whether the registrant (1) has filed all
reports required to be filed by Section 13 or 15(d) of the Securities Exchange
Act of 1934 during the preceding 12 months (or for such shorter period that
the registrant was required to file such reports), and (2) has been subject to
such filing requirements for the past 90 days. Yes  X .  No    .
                                                   ---      ---

         Indicate by check mark if disclosure of delinquent filers pursuant to
Item 405 of Regulation S-K is not contained herein, and will not be contained,
to the best of registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. [ X ].

         Indicate by check mark whether the registrant is a shell company (as
defined in Rule 12b-2 of the Exchange Act). Yes   .  No  X .
                                               ---      ---

                                      1

<PAGE>
<PAGE>

         Indicate by check mark whether the registrant is a large accelerated
filer, an accelerated filer or a non-accelerated filer. See definition of
"accelerated filer and large accelerated filer" in Rule 12b-2 of the Exchange
Act. (check one):
  Large Accelerated Filer     Accelerated Filer  X    Non-Accelerated Filer
                         ---                    ---                         ---

         State the aggregate market value of the voting stock held by
non-affiliates of the registrant as of March 31, 2006: approximately
$367,500,000.

         Indicate the number of shares outstanding of each of the registrant's
classes of common stock as of December 27, 2006: 26,970,642 shares of Common
Stock, par value $.01 per share.

         DOCUMENTS INCORPORATED BY REFERENCE

         NONE.



                                      2

<PAGE>
<PAGE>


                               EXPLANATORY NOTE

         This Amendment No. 1 on Form 10-K/A amends the Registrant's Annual
Report on Form 10-K for the fiscal year ended September 30, 2006, as
originally filed on December 27, 2006, and is being filed solely for the
purpose of amending portions of Part III and Item 15 "Exhibits, Financial
Statement Schedules of Part IV" to include certain information required
therein in lieu of incorporating such information by reference from the
definitive proxy statement for its 2007 Annual Meeting of Shareholders.



------------------------------------------------------------------------------




                                      1

<PAGE>
<PAGE>

                                   PART III


Item 10.  Directors and Executive Officers of the Registrant
-------   --------------------------------------------------

DIRECTORS AND EXECUTIVE OFFICERS OF THE COMPANY

         The name, age, principal occupation or position and other
directorships with respect to each current director of the Company and each
person expected to be nominated for election as a director at the Company's
2007 Annual Meeting of Shareholders is set forth below:

CLASS II - TERM EXPIRING IN 2007; NOMINATED FOR ELECTION FOR A TERM OF THREE
YEARS EXPIRING IN 2010

         James W. Betts, age 69, has served as a Director of the Company since
1992. In 2000, he retired as Vice President Raw Materials of Great Lakes
Carbon Corp. (a producer of carbon products) in which capacity he had served
for more than the preceding five years.

CLASS II - NOMINATED FOR ELECTION FOR A TERM OF THREE YEARS EXPIRING IN 2010

         Michael D. Latta, age 65, serves as Chairman of the Board of Universe
Corporation (a construction engineering and materials distributor) and
Chairman of the Board of Res Q Tek, Inc. (a manufacturer of hydraulic and
pneumatic rescue equipment). He has served in these positions respectively
from 1997 and 1995. Prior to 1995 he was President of Safety Equipment (a
manufacturer of emergency vehicle warning equipment) from its founding in
1974.

         George E. Husman, age 61, has been appointed Chief Technology Officer
of the Company effective February 1, 2007. Prior to joining the Company, Mr.
Husman was the Associate Director for Engineering Research at the University
of Alabama at Birmingham since 2004. From 1993 to 2004, Mr. Husman served as
the Vice President, Engineering Division, at the Southern Research Institute
in Birmingham, Alabama. Prior to 1993, Mr. Husman spent 18 years at the
Materials Directorate at Wright-Patterson Air Force Base in various research
and management positions, and held various positions with BASF Structural
Materials, Inc., including Vice President for Business Development and Vice
President for Research & Development.

CLASS III - TERM EXPIRING IN 2008

         Zsolt Rumy, age 64, is the founder of the Company and has served as
its Chairman, Chief Executive Officer and President and as a Director since
1975. Prior to founding the Company, Mr. Rumy served as Process Engineer and
Industrial Marketing Manager for Monsanto Company, Accounts Manager for
General Electric Company and Technical Sales Representative for W.R. Grace
Company.

         Charles A. Dill, age 67, has served as a Director of the Company
since 1992. He is currently a Principal of Two Rivers Associates, LLC, a
private equity firm, which is the successor to Gateway Associates, LP, where
Mr. Dill was a General Partner since 1995. He served as Chief Executive
Officer of Bridge Information Systems, Inc. (a provider of online data and
trading systems to institutional investors) from 1990 to 1995. Mr. Dill was
President of AVX Corporation (a NYSE-listed manufacturer of electronic
components) from 1987 to 1990, after spending his earlier career in a number
of executive positions with Emerson Electric. Mr. Dill serves as a Director of
Stifel Financial Corp., the parent of Stifel, Nicolaus & Company (a securities
brokerage and investment banking firm) and TransAct Technologies (a
manufacturer of transaction-based printers), as well as several private
companies.

                                      2

<PAGE>
<PAGE>

CLASS I - TERM EXPIRING IN 2009

         Linn H. Bealke, age 62, has served as a Director of the Company since
1992. For more than five years prior to October 2002, he was President and
Director of Mississippi Valley Bancshares, Inc. (a bank holding company) and
Vice Chairman of Southwest Bank of St. Louis (a commercial bank). In October
2002, Mississippi Valley Bancshares, Inc. was merged into Marshall and Ilsley
Corporation. Mr. Bealke continued to serve as Vice Chairman of Southwest Bank
of St. Louis until his retirement in December 2004.

         John L. Kardos, age 67, has served as a Director of the Company since
1992. For more than the six years before his retirement in May 2005, he was
Lopata Professor of Chemical Engineering at Washington University, St. Louis,
Missouri. He currently holds the position of Professor Emeritus. From fiscal
2000 to the present, Dr. Kardos has served as a consultant to the Company on a
part-time basis to assist the Company in evaluating technology matters. From
1971 to 1991, he was Chairman of the Graduate Program in Materials Science and
Engineering and Director of the Materials Research Laboratory of Washington
University. He also served as Chairman of the Department of Chemical
Engineering of Washington University from 1991 to 1998.

         For information regarding the executive officers of the Company,
please see Item 4A of Part 1 of this report.

BOARD OF DIRECTORS AND COMMITTEES

         During the fiscal year ended September 30, 2006, the Board of
Directors of the Company met seven times. The Board has determined that each
of Messrs. Bealke, Betts and Dill and Dr. Kardos qualify as independent
directors in accordance with the listing standards and rules of the Nasdaq
Stock Market, Inc. ("Nasdaq"). The Board has a standing Audit Committee and
Compensation Committee. Each director attended not less than 75% or more of
the aggregate number of meetings of the Board of Directors and committees of
which such director was a member during fiscal 2006. It is the Company's
policy to strongly encourage its Board members to attend the annual meeting of
shareholders. At the last Annual Meeting, all of the directors were in
attendance.

         The members of the Audit Committee are Messrs. Betts and Dill, all of
whom are considered independent under the listing standards of Nasdaq. Mr.
Dill serves as the Audit Committee's financial expert. The Audit Committee
operates under a written charter adopted by the Board of Directors. The Audit
Committee reviews the scope of the Company's engagement of its independent
public accountant and their reports. The Audit Committee also meets with the
financial staff of the Company to review accounting procedures and reports. It
is anticipated that Mr. Latta will be appointed to the Audit Committee
effective as of his election as a Director at the Company's 2007 Annual
Meeting of Shareholders. Mr. Latta is considered independent under the listing
standards and rules of Nasdaq. The Audit Committee met four times in fiscal
2006.

         The Compensation Committee is comprised of Messrs. Betts and Dill,
each of whom is considered independent under the listing standards of Nasdaq.
The Compensation Committee is authorized to review and make recommendations to
the Board of Directors regarding the salaries and bonuses to be paid executive
officers and to administer the Company's Long Term Incentive Plan. Members of
the Compensation Committee met one time in fiscal 2006 and consulted
informally with each other and with members of management from time to time in
fiscal 2006.

         Nominees for director are recommended for selection by the Board of
Directors by a majority of the independent directors. In light of the number
of independent directors and the lack of nominations by shareholders in the
past, the Board of Directors has not adopted a formal nominating committee or
nominating committee charter. The independent directors will consider nominees
recommended by shareholders. Any shareholder wishing to nominate a candidate
for director at a shareholders meeting must submit a proposal as


                                      3

<PAGE>
<PAGE>

described under "Proposals of Shareholders" and furnish certain information
about the proposed nominee. The notice submission should include information
on the candidate for director, including the proposed candidate's name, age,
business address, residence address, principal occupation or employment for
the previous five years, and class or series and number of shares of the
Company's Common Stock owned beneficially or of record. In considering a
potential nominee for the Board, shareholders should note that the rules of
Nasdaq require that a majority of the Board of Directors be independent, as
defined by Nasdaq rules. Further, the candidates should evidence: personal
characteristics of the highest personal and professional ethics, integrity and
values; an inquiring and independent mind and practical wisdom and mature
judgment; broad training and experience at the policy-making level in
business, government or community organizations; expertise that is useful to
the Company and complementary to the background and experience of other Board
members; willingness to devote a required amount of time to carrying out the
duties and responsibilities of Board membership; commitment to serve on the
Board over a period of several years to develop knowledge about the Company,
its strategy and its principal operations; willingness to represent the best
interests of all constituencies and objectively appraise management
performance; and involvement in activities or interests that do not create a
conflict with the director's responsibilities to the Company. The notice
submission should be addressed to the Company's Board of Directors, c/o Zoltek
Companies, Inc., 3101 McKelvey Road, St. Louis, Missouri 63044.

         Shareholders who desire to communicate with members of the Board
should send correspondence addressed to Board of Directors, c/o Zoltek
Companies, Inc., 3101 McKelvey Road, St. Louis, Missouri 63044. All
appropriate shareholder correspondence is forwarded directly to the members of
the Board of Directors. The Company does not, however, forward sales or
marketing materials or correspondence not clearly identified as shareholder
correspondence.

SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

         Section 16(a) of the Securities Exchange Act of 1934, as amended,
requires that the Company's executive officers and directors, and persons who
own more than ten percent of the Company's outstanding stock, file reports of
ownership and changes in ownership with the Securities and Exchange
Commission. To the knowledge of management, based solely on its review of such
reports furnished to the Company and written representations that no other
reports were required to be filed, all Section 16(a) filing requirements
applicable to the Company's officers, directors and greater than ten percent
beneficial owners were complied with during the fiscal year ended September
30, 2006.

CODE OF ETHICS

         The Company has adopted a Senior Executives Code of Ethics that
applies to the Company's executive officers. The Senior Executives Code of
Ethics may be obtained free of charge by sending a written request to Jill A.
Schmidt, Zoltek Companies, Inc., 3101 McKelvey Road, St. Louis, Missouri
63044.

Item 11.  Executive Compensation
--------  ----------------------

DIRECTORS' FEES

         Directors who are not also employees of the Company are paid $750 per
board meeting attended. In addition, each of the directors who is not also an
employee of the Company (an "Eligible Director") participates in the Zoltek
Directors Stock Option Plan (the "Directors Plan"). The Directors Plan
provides for the granting of non-qualified stock options to Eligible
Directors. Under the Directors Plan, each person who is an Eligible Director
on the first business day after the date of the Company's annual meeting of
shareholders is granted options to acquire 7,500 shares of Common Stock. In
addition, newly elected directors who are not also employees also receive an
initial grant of options to purchase 7,500 at the time of their election. The
Directors Plan otherwise does not establish a limit on the aggregate number of
options that may be granted thereunder.


                                      4

<PAGE>
<PAGE>

Options granted pursuant to the Directors Plan entitle the director to
purchase the Company's Common Stock at a price equal to the Fair Market Value
(as defined in the Directors Plan) on the date of grant. The option by its
terms is not transferable by the director except by will or the laws of
descent and distribution or pursuant to a qualified domestic relations order.
The option is exercisable during the director's lifetime solely by the
director. Each option is immediately exercisable as to any or all shares and
may be exercised at any time or from time to time. Options that are
outstanding and unexercised at the time the holder ceases to be a director of
the Company for any reason terminate on the first to occur of the expiration
date of the option or the expiration of 24 months after the date the holder
ceases to be a director. Unless exercised or terminated sooner, each option
expires on the tenth anniversary of the date of grant.

COMPENSATION OF EXECUTIVE OFFICERS

         For the fiscal years ended September 30, 2006, 2005 and 2004, the
following table sets forth summary information concerning compensation awarded
or paid to, or earned by, the Chief Executive Officer, Chief Financial Officer
and former Chief Operating Officer, who were the only executive officers or
former executive officers of the Company whose salary and bonus exceeded
$100,000 for the fiscal year ended September 30, 2006.

<TABLE>
<CAPTION>
                                                                          Long Term
                                                                        Compensation
                                                    Annual            ----------------
                                                Compensation            Securities
                                                ------------            Underlying
Name and Principal Position                  Year     Salary($)       Options/SARs(#)
---------------------------                  ----     ---------       ---------------
<C>                                          <C>      <C>             <C>
Zsolt Rumy                                   2006     $270,833               --/--
Chairman of the Board, President             2005     $225,000               --/--
and Chief Executive Officer                  2004     $225,000               --/--

Kevin Schott                                 2006     $200,000           10,000/--
Chief Financial Officer                      2005     $184,375               --/--
                                             2004     $202,083(1)        40,000/--

David Harding                                2006     $140,625               --/--
Former Chief Operating Officer(2)            2005     $131,250          100,000/--

<FN>
-------------------

(1)  Mr. Schott became the Company's Chief Financial Officer as of March 1,
     2004; prior to that date he was a consultant for the Company. Included in
     his compensation for fiscal 2004 is $100,000 in fees paid to him prior to
     March 1, 2004.

(2)  Mr. Harding's employment with the Company terminated effective January
     19, 2006.
</TABLE>





                                      5

<PAGE>
<PAGE>

OPTION GRANTS IN LAST FISCAL YEAR

         The following table sets forth information concerning stock option
grants made in the year ended September 30, 2006, to the executive officers
and former executive officers named in the Compensation of Executive Officers
Table.

<TABLE>
<CAPTION>
                                           INDIVIDUAL GRANT
                         -------------------------------------------------------     POTENTIAL REALIZABLE VALUE
                                        PERCENT OF                                    AT ASSUMED ANNUAL RATES
                          NUMBER OF    TOTAL OPTIONS                                 OF STOCK PRICE APPRECIATION
                          SECURITIES     GRANTED TO                                       FOR OPTION TERM(2)
                          UNDERLYING    EMPLOYEES IN    EXERCISE OR                  ---------------------------
                           OPTIONS         FISCAL       BASE PRICE     EXPIRATION
   NAME                  GRANTED (#)      YEAR (%)        ($/SH)         DATE(1)        5% ($)          10% ($)
   ----                  -----------      --------        ------         -------        ------          -------
<C>                        <C>              <C>           <C>           <C>             <C>             <C>
Zsolt Rumy                     --            --              --             --               --               --
Kevin Schott               10,000(3)        6.5%          $8.60         12/31/2016      $54,085         $137,062
David Harding                  --            --              --             --               --               --

<FN>
-------------------

(1)  The options expire on the earlier of: ten years after grant; three months
     after termination of employment, except in the case of retirement, death
     or total disability; or 12 months after termination of employment in the
     case of retirement, death or total disability.

(2)  The indicated 5% and 10% rates of appreciation are provided to comply
     with Securities and Exchange Commission regulations and do not
     necessarily reflect our views as to the likely trend in the price of the
     Common Stocks. Actual gains, if any, on stock option exercises and common
     stock holdings will be dependent on, among other things, the future
     performance of the Common Stock and overall market conditions. There can
     be no assurance that the amounts reflected above will be achieved.
     Additionally, these values do not take into consideration the provisions
     of the options providing for nontransferability or delayed
     exercisability.

(3)  The options become exercisable with respect to one-half of the total
     option shares on October 1, 2006, and the remainder of the options become
     exercisable on October 1, 2007.
</TABLE>

AGGREGATED OPTION EXERCISES IN LAST FISCAL YEAR AND FISCAL YEAR-END OPTION
VALUES

         The following table sets forth information with respect to the
exercise of stock options by the executive officers and former executive
officer named in the Summary Compensation Table during the year ended
September 30, 2006, and the number of exercisable and unexercisable stock
options at September 30, 2006, as well as the value of such stock options
having an exercise price lower than the closing price on September 30, 2006
("in-the-money" options) held by the executive officers and former executive
officer named in the Summary Compensation Table.

<TABLE>
<CAPTION>
                                                                                                    VALUE OF
                                                                   NUMBER OF SECURITIES            UNEXERCISED
                                                                  UNDERLYING UNEXERCISED          IN-THE-MONEY
                                                                     OPTIONS AT FISCAL          OPTIONS AT FISCAL
                                    SHARES                             YEAR-END (#)               YEAR-END ($)
                                 ACQUIRED ON         VALUE             EXERCISABLE/               EXERCISABLE/
       NAME                      EXERCISE (#)     REALIZED ($)         UNEXERCISABLE             UNEXERCISABLE(1)
       ----                      ------------     ------------         -------------             -------------
<C>                                <C>            <C>                   <C>                      <C>
Zsolt Rumy                         225,000        $4,656,000                -- / --                    $-- / --

Kevin Schott                        25,000          $511,350            -- / 35,000               -- / $680,150

David Harding                       37,500          $523,875                -- / --                     -- / --

<FN>
-------------------

(1) Based on a price per share of $25.55, the closing price of our common
stock on September 29, 2006.
</TABLE>

                                      6

<PAGE>
<PAGE>

Item 12.  Security Ownership of Certain Beneficial Owners and Management and
-------   ------------------------------------------------------------------
Related Stockholder Matters
---------------------------

VOTING SECURITIES AND PRINCIPAL HOLDERS THEREOF

         The following table includes information as to the only persons known
to management of the Company to beneficially own 5% or more of the Company's
outstanding Common Stock as of January 5, 2007:

<TABLE>
<CAPTION>
                                                         Number of Shares              Percent of Outstanding
Name and Address of Beneficial Owner                   Beneficially Owned(1)               Common Stock(2)
------------------------------------                   ---------------------          ------------------------
<C>                                                         <C>                                 <C>
Zsolt Rumy                                                  6,257,709(3)                        23.1%

Luxor Capital Group, L.P.                                   1,540,752(4)                         5.7%

<FN>
-------------------

(1)  The listed persons have sole voting and investment power with respect to
     the reported shares.

(2)  The percentage calculation is based upon 27,015,642 shares of the
     Company's Common Stock that were issued and outstanding as of January 5,
     2007 and the number of shares subject to options, warrants or conversion
     rights exercisable by such person within 60 days of January 5, 2007.

(3)  The business address of Mr. Rumy is c/o Zoltek Companies, Inc., 3101
     McKelvey Road, St. Louis, Missouri 63044.

(4)  The information is based on a Schedule 13G, dated December 15, 2006,
     jointly filed by Luxor Capital Group, LP, Luxor Capital Partners, LP, LCG
     Select, LLC, Luxor Capital Partners Offshore, Ltd., LCG Select Offshore,
     Ltd, Luxor Management, LLC, LCG Holdings, LLC and Christian Leon. The
     business address for each of Luxor Capital Partners, LP, LCG Select, LLC,
     Luxor Capital Group, LP, Luxor Management LLC, LCG Holdings, LLC and Mr.
     Leon is 767 Fifth Avenue, 19th Floor, New York, New York 10153. The
     business address of each of LCG Select, LLC and Luxor Capital Partners
     Offshore, Ltd, is c/o M&C Corporate Services Limited, P.O. Box 309GT,
     Usland House, South Church Street, George Town, Grand Cayman, Cayman
     Islands.
</TABLE>

SECURITY OWNERSHIP BY MANAGEMENT

         The following table indicates, as of January 5, 2007, the beneficial
ownership of the Company's Common Stock by each director of the Company, each
nominee for election as a director of the Company, the executive officers and
former executive officers named in the Summary Compensation Table and all
directors and executive officers of the Company as a group:

<TABLE>
<CAPTION>
                                                                     Number of Shares
Name of Beneficial Owner                                            Beneficially Owned        Percent of Class(1)
------------------------                                            ------------------        -------------------
<C>                                                                     <C>                           <C>
Zsolt Rumy                                                              6,257,709                     23.1%
Kevin Schott                                                               40,000                         *
Linn H. Bealke                                                            373,615(2)                   1.3%
James W. Betts                                                             96,682(3)                      *
Charles A. Dill                                                           244,861(4)                   1.0%
John L. Kardos                                                             85,000(5)                      *
Michael D. Latta                                                           67,442                         *
George E. Husman                                                               --                         *
All directors and executive officers as a group (9 persons)             7,165,309(6)                  26.3%


                                      7

<PAGE>
<PAGE>

<FN>
-------------------

*   Less than one percent

(1)  Based upon 27,015,642 shares of the Company's Common Stock issued and
     outstanding as of January 5, 2007 and, for each director or executive
     officer or the group, the number of shares subject to options, warrants
     or conversion rights that may be acquired upon exercise thereof by such
     director or executive officer or the group within 60 days of January 5,
     2007.

(2)  Includes 52,500 shares subject to presently exercisable stock options.

(3)  Includes 75,000 shares subject to presently exercisable stock options.

(4)  Includes (i) 30,000 shares subject to presently exercisable stock options
     and (ii) an aggregate of 28,571 shares deemed to be beneficially owned by
     Mr. Dill by virtue of his right to convert certain convertible debentures
     issued by the Company into Common Stock.

(5)  Includes 75,000 shares subject to presently exercisable stock options.

(6)  Includes (i) 232,500 shares subject to presently exercisable stock
     options and (ii) an aggregate of 28,571 shares deemed to be beneficially
     owned by Mr. Dill by virtue of his right to convert certain convertible
     debentures issued by the Company into Common Stock.
</TABLE>

EQUITY COMPENSATION PLAN INFORMATION

         The following table shows the total number of outstanding options and
shares available for future issuances of options under the Company's existing
stock option plans as of September 30, 2006.

<TABLE>
                                      EQUITY COMPENSATION PLAN INFORMATION
                                      ------------------------------------

<CAPTION>
                                                                                             NUMBER OF SECURITIES
                                                                                              REMAINING AVAILABLE
                                                                     WEIGHTED AVERAGE         FOR FUTURE ISSUANCE
                                       NUMBER OF SECURITIES TO       EXERCISE PRICE OF           UNDER EQUITY
                                       BE ISSUED UPON EXERCISE      OUTSTANDING OPTIONS       COMPENSATION PLANS
                                       OF OUTSTANDING OPTIONS          UNDER EQUITY          (EXCLUDING SECURITIES
                                         WARRANTS AND RIGHTS        WARRANTS AND RIGHTS       REFLECTED IN COLUMN)
          PLAN CATEGORY                          (#)                        ($)                       (#)
          -------------                -----------------------      -------------------      ---------------------
<C>                                         <C>                             <C>                   <C>
Equity Compensation Plans
Approved by Security Holders                552,834(1)                      $10.94                696,000(1)

Equity Compensation Plans Not
Approved by Security Holders                      -(2)                           -                      -(2)

Total                                       552,834                         $10.94                696,000

<FN>
-------------------

(1) Under the Company's Directors Stock Option Plan, there is at all times
    reserved for issuance a number of shares of Common Stock equal to the
    total number of shares then issuable pursuant to all option grants which
    are then outstanding under such plan.

(2) The Company currently has no equity compensation plans that are not
    approved by security holders.
</TABLE>

                                      8

<PAGE>
<PAGE>

Item 13.  Certain Relationships and Related Transactions
--------  ----------------------------------------------

CERTAIN TRANSACTIONS

         In February 2003, the Company issued and sold to a group of 14
investors, including Messrs. Bealke, Dill, McDonnell (who then served as a
director) and Rumy, subordinated convertible debentures in the aggregate
principal amount of $8.1 million. During fiscal 2006, the Company paid
interest under the convertible debentures of $76,352 to Mr. Rumy.

         During fiscal 2006, in connection with the Company's operations, the
Company from time to time chartered an airplane from a corporation wholly
owned by Mr. Rumy, the Chairman, President and Chief Executive Officer of the
Company. The total of all such charter payments made by the Company during
fiscal 2006 was $105,695.

         During fiscal 2006, Dr. Kardos, who is a director of the Company,
performed various consulting services for the Company related to evaluating
technology aspects of the Company's business. During fiscal 2006, the Company
paid Dr. Kardos an aggregate of $92,166 for such consulting services.

         Mr. Rumy, the Chairman and Chief Executive Officer of the Company,
has entered into a Continuing Limited Guaranty Agreement, dated as of December
21, 2006 (the "Limited Guaranty"), pursuant to which Mr. Rumy agreed to
guarantee payment to Southwest Bank of St. Louis, the Company's primary U.S.
lender (the "Bank"), of up to $10 million of the obligations of the Company to
the Bank with respect to a standby letter of credit in the face amount of up
to $40 million which the Bank has agreed to issue for the account of the
Company and certain of its subsidiaries to secure the payment of a bond to
enable the Company to continue to defend certain pending litigation. Under the
terms of the Limited Guaranty, Mr. Rumy will be released in full upon either
(i) receipt by the Bank of certain documents relating to the Company's grant
to the Bank of a lien on the Company's headquarters facilities and its two
United States carbon fiber manufacturing facilities, or (ii) a release by the
Bank of its lien on such real estate. In addition to the foregoing, pursuant
to a Term Loan Promissory Note, dated as of December 21, 2006 (the "Term Loan
Note"), Mr. Rumy has made a $10 million unsecured loan to the Company. The
Term Loan Note is due and payable on January 2, 2008. Interest on the unpaid
principal amount of the Term Loan Note is due and payable monthly in arrears
commencing January 30, 2007, and bears interest at a rate per annum equal to
the rate per annum then being paid by Mr. Rumy to an unaffiliated third party
to obtain funds necessary for Mr. Rumy to make the loan to the Company
evidenced by the Term Loan Note, subject to increase by 2% per annum from and
during an event of default. The terms of the Limited Guaranty and the Term
Loan Note have been approved by the Company's Board of Directors and Audit
Committee.

         The Company believes that all of the transactions with affiliates set
forth above were made on terms not less favorable to the Company than would
have been obtained from unaffiliated third parties.

Item 14.  Principal Accountant Fees and Services
--------  --------------------------------------

PRINCIPAL AUDITORS FEES AND SERVICES

         PricewaterhouseCoopers LLP served as the Company's independent
accountants for fiscal 2006. The Board of Directors has not yet appointed
independent accountants to be the Company's auditors for fiscal 2007. The
Company expects that the Company's auditors for fiscal 2006 will be appointed
by the end of the second quarter of fiscal 2007.

         The following table displays the aggregate fees for professional
audit services for the audit of the financial statements for the fiscal years
ended September 30, 2006 and 2005 and fees billed for other services during
those periods by PricewaterhouseCoopers LLP.

                                      9

<PAGE>
<PAGE>

<TABLE>
<CAPTION>
                                                                 2006            2005
                                                                 ----            ----
                      <C>                                      <C>            <C>
                      Audit fees(1)........................    $765,286       $1,097,874
                      Audit related-fees...................          --               --
                      Tax fees.............................          --               --
                      All other fees.......................                           --
                                                               --------       ----------
                      Total................................    $765,286       $1,097,874
                                                               ========       ==========

<FN>
-------------------

(1)  Audit fees consisted of audit work performed with respect to the
     Company's financial statements as well as work generally only the
     independent auditors can reasonably be expected to provide, such as
     statutory audits.
</TABLE>

         Since the Audit Committee adopted the pre-approval policy described
below, the Audit Committee pre-approved under that policy fees, which on a
fiscal year basis, represented 100% of the "Audit fees" in fiscal years 2006
and 2005.

         Consistent with Securities and Exchange Commission requirements
regarding auditor independence, the Audit Committee has adopted a policy to
pre-approve all audit and permissible non-audit services provided by the
independent auditor. Under the policy, the Committee must pre-approve services
prior to commencement of the specified service. The Audit Committee
periodically reviews reports summarizing the services, including fees,
provided by the independent auditor; a listing of pre-approved services
provided; and a current projection presented similar to that included in this
proxy statement, of the estimated annual fees to be paid to the independent
auditors.

                                    PART IV

Item 15.  Exhibits and Financial Statement Schedule
--------  -----------------------------------------

         (a) (1) Financial statements: The following financial statements were
included in Item 8 of the Registrant's Annual Report on Form 10-K for the
fiscal year ended September 30, 2006, as originally filed on December 27,
2006:

                  Report of Independent Registered Public Accounting Firm

                  Consolidated Balance Sheet as of September 30, 2006
                  and 2005

                  Consolidated Statement of Operations for the years ended
                  September 30, 2006, 2005 and 2004

                  Consolidated Statement of Changes in Shareholders' Equity
                  for the years ended September 30, 2006, 2005 and 2004

                  Consolidated Statement of Cash Flows for the years ended
                  September 30, 2006, 2005 and 2004

                  Notes to Consolidated Financial Statements

                  (2) The following financial statement schedule and
Independent Registered Public Accounting Firm's report thereon were included
in Part IV of the Registrant's Annual Report on Form 10-K for the fiscal year
ended September 30, 2006, as originally filed on December 27, 2006:

                                      10

<PAGE>
<PAGE>

         Report of Independent Registered Public Accounting Firm on
         Financial Statement Schedule

         12-09 Valuation and Qualifying Accounts and Reserves

                      Schedules other than those listed above have been
omitted because they are either not required or not applicable, or because the
information is presented in the consolidated financial statements or the notes
thereto.

                  (3) The following exhibits are filed herewith or
incorporated by reference herein, as indicated:

         3.1      Restated Articles of Incorporation of the Registrant, filed
                  as Exhibit 3.1 to Registrant's Registration Statement on
                  Form S-1 (Reg. No. 33-51142) is incorporated herein by this
                  reference

         3.2      Restated By-Laws of the Registrant, as currently in effect,
                  filed as Exhibit 3.2 to Registrant's Registration Statement
                  on Form S-1 (Reg. No. 33-51142) is incorporated herein by
                  this reference

         4.1      Form of certificate for Common Stock, filed as Exhibit 4.1
                  to Registrant's Registration Statement on Form S-1 (Reg. No.
                  33-51142) is incorporated herein by this reference

         4.2      Form of Warrant, dated May 11, 2001, issued to Southwest
                  Bank of St. Louis with respect to 12,500 shares of
                  Registrant's Common Stock is filed herewith

         4.3      Subordinated Convertible Debenture Purchase Agreement, dated
                  as of February 13, 2003, by and among Zoltek Companies, Inc.
                  and the investors named therein, filed as Exhibit 4.1 to
                  Registrant's Current Report on Form 8-K dated February 18,
                  2003 is incorporated herein by reference

         4.4      Form of Subordinated Debenture, filed as Exhibit 4.2 to
                  Registrant's Current Report on Form 8-K dated February 18,
                  2003 is incorporated herein by reference

         4.5      Form of Warrant, filed as Exhibit 4.3 to Registrant's
                  Current Report on Form 8-K dated February 18, 2003 is
                  incorporated herein by reference

         4.6      Securities Purchase Agreement, dated as of December 19,
                  2003, by and among Zoltek Companies, Inc. and the investors
                  named therein, filed as Exhibit 4.6 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003 is incorporated herein by reference

         4.7      Form of 6% Convertible Debenture, filed as Exhibit 4.7 to
                  Registrant's Annual Report on Form 10-K for the fiscal year
                  ended September 30, 2003 is incorporated herein by reference

         4.8      Form of Warrant, filed as Exhibit 4.8 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003 is incorporated herein by reference

         4.9      Securities Purchase Agreement, dated as of March 11, 2004,
                  by and among Zoltek Companies, Inc. and the investors named
                  therein, filed as Exhibit 4.2 to Registrant's Registration
                  Statement on Form S-3 (Reg. No. 333-115043) is incorporated
                  herein by reference

         4.10     Form of 6% Convertible Debenture, filed as Exhibit 4.3 to
                  Registrant's Registration Statement on Form S-3 (Reg. No.
                  333-115043) is incorporated herein by reference

         4.11     Form of Warrant, filed as Exhibit 4.4 to Registrant's
                  Registration Statement on Form S-3 (Reg. No. 333-115043) is
                  incorporated herein by reference

                                      11

<PAGE>
<PAGE>

         4.12     Loan and Warrant Agreement, dated as of October 14, 2004,
                  filed as Exhibit 4.1 to Registrant's Current Report on Form
                  8-K dated October 19, 2004 is incorporated herein by
                  reference

         4.13     Security Agreement, dated as of October 14, 2004, filed as
                  Exhibit 4.3 to Registrant's Current Report on Form 8-K dated
                  October 19, 2004 is incorporated herein by reference

         4.14     Mortgage Agreement, dated as of October 14, 2004, filed as
                  Exhibit 4.4 to Registrant's Current Report on Form 8-K dated
                  October 19, 2004 is incorporated herein by reference

         4.15     Form of Warrant, filed as Exhibit 4.5 to Registrant's
                  Current Report on Form 8-K dated October 19, 2004 is
                  incorporated herein by reference

         4.16     Loan and Warrant Agreement, dated as of February 9, 2005, by
                  and among the Registrant, the Lenders and the Agent, filed
                  as Exhibit 4.1 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended December 31, 2004 and
                  incorporated herein by reference

         4.17     Form of Senior Convertible Note, dated as of February 9,
                  2005, filed as Exhibit 4.2 to the Registrant's Quarterly
                  Report on Form 10-Q for the quarter ended December 31, 2004
                  and incorporated Herein by reference

         4.18     Form of Warrant, dated as of February 9, 2005, filed as
                  Exhibit 4.3 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended December 31, 2004 and
                  incorporated herein by reference

         4.19     Form of Registration Rights Agreement, dated as of February
                  9, 2005, filed as Exhibit 4.4 to the Registrant's Quarterly
                  Report on Form 10-Q for the quarter ended December 31, 2004
                  and incorporated herein by reference

         4.20     Loan and Warrant Agreement, as of September 29, 2005, among
                  the Registrant, the Lenders and the Agent, filed as Exhibit
                  4.1 to the Registrant's Current Report on Form 8-K dated
                  September 29, 2005 and incorporated herein by reference

         4.21     Form of Note, filed as Exhibit 4.2 to the Registrant's
                  Current Report on Form 8-K dated September 29, 2005 and
                  incorporated herein by reference

         4.22     Form of Warrant, filed as Exhibit 4.3 to the Registrant's
                  Current Report on Form 8-K dated September 29, 2005 and
                  incorporated herein by reference

         4.23     Registration Rights Agreement, dated as of September 30,
                  2005, by and among the Registrant and the Lenders parties
                  thereto, filed as Exhibit 4.4 to the Registrant's Current
                  Report on Form 8-K dated September 29, 2005 and incorporated
                  herein by reference

         4.24     Waiver and Consent, dated as of February 3, 2006, by and
                  among the Registrant and the Lender parties thereto, filed
                  as Exhibit 4.5 to the Registrant's Current Report on Form
                  8-K dated February 6, 2006 and incorporated herein by
                  reference

         4.25     Amendment No. 1 to Loan and Warrant Agreement and
                  Registration Rights Agreement among the Registrant and the
                  Lender parties thereto, filed as Exhibit 4.2 to the
                  Registrant's Current Report on Form 8-K dated April 28, 2006
                  and incorporated herein by reference

         4.26     Form of Note, filed as Exhibit 4.3 to the Registrant's
                  Current Report on Form 8-K dated April 28, 2006 and
                  incorporated herein by reference

         4.27     Form of Warrant, filed as Exhibit 4.4 to the Registrant's
                  Current Report on Form 8-K dated April 28, 2006 and
                  incorporated herein by reference

                                      12

<PAGE>
<PAGE>

         10.1     Loan Agreement, dated December 29, 1989, by and between
                  Zoltek Corporation and Southwest Bank of St. Louis, as
                  amended by letter, dated August 13, 1992, filed as Exhibit
                  10.7 to Registrant's Registration Statement on Form S-1
                  (Reg. No. 33-51142) is incorporated herein by this reference

         10.2     Zoltek Companies, Inc. Long Term Incentive Plan, filed as
                  Appendix B to Registrant's definitive proxy statement for
                  the 1997 Annual Meeting of Shareholders is incorporated
                  herein by this reference*

         10.3     Zoltek Companies, Inc. Amended and Restated Directors Stock
                  Option Plan, filed as Exhibit 10.1 to Registrant's Quarterly
                  Report on Form 10-Q dated August 13, 1999, is incorporated
                  herein by this reference*

         10.5     Precursor Agreement, dated as of July 1, 1994, by and
                  between Zoltek Corporation and Courtaulds Fibres Limited,
                  filed as Exhibit 10.9 to Registrant's Annual Report on Form
                  10-K for the fiscal year ended September 30, 1994, is
                  incorporated herein by this reference (An application for
                  confidential treatment has been made for a portion of
                  Exhibit 10.5.)

         10.6     Materials Supply Agreement, dated as of June 15, 1994, by
                  and between Zoltek Companies, Inc. and The B.F. Goodrich
                  Company, filed as Exhibit 10.10 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  1994, is incorporated herein by this reference (An
                  application for confidential treatment has been made for a
                  portion of Exhibit 10.6.)

         10.8     Promissory Note, dated November 14, 1994, by and between
                  Zoltek Corporation and Southwest Bank of St. Louis, filed as
                  Exhibit 10.2 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended March 31, 1995, is incorporated
                  herein by this reference

         10.10    Credit Agreement, dated May 11, 2001, between Southwest Bank
                  of St. Louis and Zoltek Companies, Inc., Zoltek Corporation,
                  Cape Composites, Inc., Engineering Technology Corporation,
                  Zoltek Properties, Inc., and Hardcore Composites Operations,
                  LLC, filed as Exhibit 10.1 to Registrant's Quarterly Report
                  on Form 10-Q for the quarter ended June 30, 2001 is
                  incorporated herein by reference

         10.11    First Amendment to Credit Agreement, dated as of February
                  13, 2003, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Cape Composites, Inc., Engineering Technology
                  Corporation, Zoltek Properties, Inc. and Southwest Bank of
                  St. Louis, filed as Exhibit 10.1 to Registrant's Current
                  Report on Form 8-K dated February 18, 2003 is incorporated
                  herein by reference

         10.12    Zoltek Companies, Inc. 2003 Long-Term Equity Incentive Plan,
                  filed as Appendix A to Registrant's definitive proxy
                  statement for the 2002 Annual Meeting of Shareholders is
                  incorporated herein by reference*

         10.14    Second Amendment to Credit Agreement, dated as of January
                  13, 2004, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Cape Composites, Inc., Engineering Technology
                  Corporation, Zoltek Properties, Inc. and Southwest Bank of
                  St. Louis filed as Exhibit 10.14 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003, is incorporated herein by this reference

         10.15    Third Amendment to Credit Agreement, dated as of December
                  21, 2006, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Engineering Technology Corporation, Zoltek
                  Properties, Inc. and Southwest Bank of St. Louis, filed as
                  Exhibit 10.4 to the Registrant's Current Report on Form 8-K
                  dated December 21, 2006 is incorporated herein by reference.

         10.16    Amended and Restated Revolving Credit Note, dated December
                  21, 2006, in favor of Southwest Bank of St. Louis in the
                  original principal amount of $6,719,770.39, filed as Exhibit
                  10.5 to the Registrant's Current Report on Form 8-K dated
                  December 21, 2006 is incorporated herein by reference.

         10.17    Continuing Limited Guarantee Agreement, dated as of December
                  21, 2006, executed by Zsolt Rumy in favor of Southwest Bank
                  of St. Louis, filed as Exhibit 10.6 to the Registrant's
                  Current Report on Form 8-K dated December 21, 2006 is
                  incorporated herein by reference.

                                      13

<PAGE>
<PAGE>

         10.18    Term Loan Promissory Note, dated December 21, 2006, in favor
                  of Zsolt Rumy in the original principal amount of
                  $10,000,000, filed as Exhibit 10.7 to the Registrant's
                  Current Report on Form 8-K dated December 21, 2006 is
                  incorporated herein by reference.

         21       Subsidiaries of the Registrant filed as Exhibit 21 to
                  Registrant's Annual Report on Form 10-K for the fiscal year
                  ended September 30, 2000 is incorporated herein by this
                  reference

         23       Consent of PricewaterhouseCoopers LLP**

         31.1     Certification of Chief Executive Officer pursuant to Rule
                  13a-14(a) under the Securities Exchange Act of 1934, as
                  amended is filed herewith

         31.2     Certification of Chief Financial Officer pursuant to Rule
                  13a-14(a) under the Securities Exchange Act of 1934, as
                  amended is filed herewith

         32.1     Certification of Chief Executive Officer pursuant to 18
                  U.S.C. Section 1350, as adopted pursuant to Section 906 of
                  the Sarbanes-Oxley Act of 2002 is filed herewith

         32.2     Certification of Chief Financial Officer pursuant to 18
                  U.S.C. Section 1350, as adopted pursuant to Section 906 of
                  the Sarbanes-Oxley Act of 2002 is filed herewith


<FN>
-------------------
*  Management compensatory plan or arrangement
** Previously filed



                                      14

<PAGE>
<PAGE>

                                  SIGNATURES

         Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be signed
on its behalf by the undersigned, thereunto duly authorized.

                          ZOLTEK COMPANIES, INC.
                               (Registrant)


                          By  /s/ Zsolt Rumy
                              ------------------------------------------------
                              Zsolt Rumy, Chairman of the Board, President and
                              Chief Executive Officer

Date: January 29,  2007






                                      15

<PAGE>
<PAGE>

                                 EXHIBIT INDEX
                                 -------------

Exhibit No.       Description
-----------       -----------

         3.1      Restated Articles of Incorporation of the Registrant, filed
                  as Exhibit 3.1 to Registrant's Registration Statement on
                  Form S-1 (Reg. No. 33-51142) is incorporated herein by this
                  reference

         3.2      Restated By-Laws of the Registrant, as currently in effect,
                  filed as Exhibit 3.2 to Registrant's Registration Statement
                  on Form S-1 (Reg. No. 33-51142) is incorporated herein by
                  this reference

         4.1      Form of certificate for Common Stock, filed as Exhibit 4.1
                  to Registrant's Registration Statement on Form S-1 (Reg. No.
                  33-51142) is incorporated herein by this reference

         4.2      Form of Warrant, dated May 11, 2001, issued to Southwest
                  Bank of St. Louis with respect to 12,500 shares of
                  Registrant's Common Stock is filed herewith

         4.3      Subordinated Convertible Debenture Purchase Agreement, dated
                  as of February 13, 2003, by and among Zoltek Companies, Inc.
                  and the investors named therein, filed as Exhibit 4.1 to
                  Registrant's Current Report on Form 8-K dated February 18,
                  2003 is incorporated herein by reference

         4.4      Form of Subordinated Debenture, filed as Exhibit 4.2 to
                  Registrant's Current Report on Form 8-K dated February 18,
                  2003 is incorporated herein by reference

         4.5      Form of Warrant, filed as Exhibit 4.3 to Registrant's
                  Current Report on Form 8-K dated February 18, 2003 is
                  incorporated herein by reference

         4.6      Securities Purchase Agreement, dated as of December 19,
                  2003, by and among Zoltek Companies, Inc. and the investors
                  named therein, filed as Exhibit 4.6 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003 is incorporated herein by reference

         4.7      Form of 6% Convertible Debenture, filed as Exhibit 4.7 to
                  Registrant's Annual Report on Form 10-K for the fiscal year
                  ended September 30, 2003 is incorporated herein by reference

         4.8      Form of Warrant, filed as Exhibit 4.8 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003 is incorporated herein by reference

         4.9      Securities Purchase Agreement, dated as of March 11, 2004,
                  by and among Zoltek Companies, Inc. and the investors named
                  therein, filed as Exhibit 4.2 to Registrant's Registration
                  Statement on Form S-3 (Reg. No. 333-115043) is incorporated
                  herein by reference

         4.10     Form of 6% Convertible Debenture, filed as Exhibit 4.3 to
                  Registrant's Registration Statement on Form S-3 (Reg. No.
                  333-115043) is incorporated herein by reference

         4.11     Form of Warrant, filed as Exhibit 4.4 to Registrant's
                  Registration Statement on Form S-3 (Reg. No. 333-115043) is
                  incorporated herein by reference

         4.12     Loan and Warrant Agreement, dated as of October 14, 2004,
                  filed as Exhibit 4.1 to Registrant's Current Report on Form
                  8-K dated October 19, 2004 is incorporated herein by
                  reference

         4.13     Security Agreement, dated as of October 14, 2004, filed as
                  Exhibit 4.3 to Registrant's Current Report on Form 8-K dated
                  October 19, 2004 is incorporated herein by reference

         4.14     Mortgage Agreement, dated as of October 14, 2004, filed as
                  Exhibit 4.4 to Registrant's Current Report on Form 8-K dated
                  October 19, 2004 is incorporated herein by reference

                                      16

<PAGE>
<PAGE>

         4.15     Form of Warrant, filed as Exhibit 4.5 to Registrant's
                  Current Report on Form 8-K dated October 19, 2004 is
                  incorporated herein by reference

         4.16     Loan and Warrant Agreement, dated as of February 9, 2005, by
                  and among the Registrant, the Lenders and the Agent, filed
                  as Exhibit 4.1 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended December 31, 2004 and
                  incorporated herein by reference

         4.17     Form of Senior Convertible Note, dated as of February 9,
                  2005, filed as Exhibit 4.2 to the Registrant's Quarterly
                  Report on Form 10-Q for the quarter ended December 31, 2004
                  and incorporated Herein by reference

         4.18     Form of Warrant, dated as of February 9, 2005, filed as
                  Exhibit 4.3 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended December 31, 2004 and
                  incorporated herein by reference

         4.19     Form of Registration Rights Agreement, dated as of February
                  9, 2005, filed as Exhibit 4.4 to the Registrant's Quarterly
                  Report on Form 10-Q for the quarter ended December 31, 2004
                  and incorporated herein by reference

         4.20     Loan and Warrant Agreement, as of September 29, 2005, among
                  the Registrant, the Lenders and the Agent, filed as Exhibit
                  4.1 to the Registrant's Current Report on Form 8-K dated
                  September 29, 2005 and incorporated herein by reference

         4.21     Form of Note, filed as Exhibit 4.2 to the Registrant's
                  Current Report on Form 8-K dated September 29, 2005 and
                  incorporated herein by reference

         4.22     Form of Warrant, filed as Exhibit 4.3 to the Registrant's
                  Current Report on Form 8-K dated September 29, 2005 and
                  incorporated herein by reference

         4.23     Registration Rights Agreement, dated as of September 30,
                  2005, by and among the Registrant and the Lenders parties
                  thereto, filed as Exhibit 4.4 to the Registrant's Current
                  Report on Form 8-K dated September 29, 2005 and incorporated
                  herein by reference

         4.24     Waiver and Consent, dated as of February 3, 2006, by and
                  among the Registrant and the Lender parties thereto, filed
                  as Exhibit 4.5 to the Registrant's Current Report on Form
                  8-K dated February 6, 2006 and incorporated herein by
                  reference

         4.25     Amendment No. 1 to Loan and Warrant Agreement and
                  Registration Rights Agreement among the Registrant and the
                  Lender parties thereto, filed as Exhibit 4.2 to the
                  Registrant's Current Report on Form 8-K dated April 28, 2006
                  and incorporated herein by reference

         4.26     Form of Note, filed as Exhibit 4.3 to the Registrant's
                  Current Report on Form 8-K dated April 28, 2006 and
                  incorporated herein by reference

         4.27     Form of Warrant, filed as Exhibit 4.4 to the Registrant's
                  Current Report on Form 8-K dated April 28, 2006 and
                  incorporated herein by reference

         10.1     Loan Agreement, dated December 29, 1989, by and between
                  Zoltek Corporation and Southwest Bank of St. Louis, as
                  amended by letter, dated August 13, 1992, filed as Exhibit
                  10.7 to Registrant's Registration Statement on Form S-1
                  (Reg. No. 33-51142) is incorporated herein by this reference

         10.2     Zoltek Companies, Inc. Long Term Incentive Plan, filed as
                  Appendix B to Registrant's definitive proxy statement for
                  the 1997 Annual Meeting of Shareholders is incorporated
                  herein by this reference*

         10.3     Zoltek Companies, Inc. Amended and Restated Directors Stock
                  Option Plan, filed as Exhibit 10.1 to Registrant's Quarterly
                  Report on Form 10-Q dated August 13, 1999, is incorporated
                  herein by this reference*

                                      17

<PAGE>
<PAGE>

         10.5     Precursor Agreement, dated as of July 1, 1994, by and
                  between Zoltek Corporation and Courtaulds Fibres Limited,
                  filed as Exhibit 10.9 to Registrant's Annual Report on Form
                  10-K for the fiscal year ended September 30, 1994, is
                  incorporated herein by this reference (An application for
                  confidential treatment has been made for a portion of
                  Exhibit 10.5.)

         10.6     Materials Supply Agreement, dated as of June 15, 1994, by
                  and between Zoltek Companies, Inc. and The B.F. Goodrich
                  Company, filed as Exhibit 10.10 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  1994, is incorporated herein by this reference (An
                  application for confidential treatment has been made for a
                  portion of Exhibit 10.6.)

         10.8     Promissory Note, dated November 14, 1994, by and between
                  Zoltek Corporation and Southwest Bank of St. Louis, filed as
                  Exhibit 10.2 to the Registrant's Quarterly Report on Form
                  10-Q for the quarter ended March 31, 1995, is incorporated
                  herein by this reference

         10.10    Credit Agreement, dated May 11, 2001, between Southwest Bank
                  of St. Louis and Zoltek Companies, Inc., Zoltek Corporation,
                  Cape Composites, Inc., Engineering Technology Corporation,
                  Zoltek Properties, Inc., and Hardcore Composites Operations,
                  LLC, filed as Exhibit 10.1 to Registrant's Quarterly Report
                  on Form 10-Q for the quarter ended June 30, 2001 is
                  incorporated herein by reference

         10.11    First Amendment to Credit Agreement, dated as of February
                  13, 2003, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Cape Composites, Inc., Engineering Technology
                  Corporation, Zoltek Properties, Inc. and Southwest Bank of
                  St. Louis, filed as Exhibit 10.1 to Registrant's Current
                  Report on Form 8-K dated February 18, 2003 is incorporated
                  herein by reference

         10.12    Zoltek Companies, Inc. 2003 Long-Term Equity Incentive Plan,
                  filed as Appendix A to Registrant's definitive proxy
                  statement for the 2002 Annual Meeting of Shareholders is
                  incorporated herein by reference*

         10.14    Second Amendment to Credit Agreement, dated as of January
                  13, 2004, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Cape Composites, Inc., Engineering Technology
                  Corporation, Zoltek Properties, Inc. and Southwest Bank of
                  St. Louis filed as Exhibit 10.14 to Registrant's Annual
                  Report on Form 10-K for the fiscal year ended September 30,
                  2003, is incorporated herein by this reference

         10.15    Third Amendment to Credit Agreement, dated as of December
                  21, 2006, by and among Zoltek Companies, Inc., Zoltek
                  Corporation, Engineering Technology Corporation, Zoltek
                  Properties, Inc. and Southwest Bank of St. Louis, filed as
                  Exhibit 10.4 to the Registrant's Current Report on Form 8-K
                  dated December 21, 2006 is incorporated herein by reference.

         10.16    Amended and Restated Revolving Credit Note, dated December
                  21, 2006, in favor of Southwest Bank of St. Louis in the
                  original principal amount of $6,719,770.39, filed as Exhibit
                  10.5 to the Registrant's Current Report on Form 8-K dated
                  December 21, 2006 is incorporated herein by reference.

         10.17    Continuing Limited Guarantee Agreement, dated as of December
                  21, 2006, executed by Zsolt Rumy in favor of Southwest Bank
                  of St. Louis, filed as Exhibit 10.6 to the Registrant's
                  Current Report on Form 8-K dated December 21, 2006 is
                  incorporated herein by reference.

         10.18    Term Loan Promissory Note, dated December 21, 2006, in favor
                  of Zsolt Rumy in the original principal amount of
                  $10,000,000, filed as Exhibit 10.7 to the Registrant's
                  Current Report on Form 8-K dated December 21, 2006 is
                  incorporated herein by reference.

         21       Subsidiaries of the Registrant filed as Exhibit 21 to
                  Registrant's Annual Report on Form 10-K for the fiscal year
                  ended September 30, 2000 is incorporated herein by this
                  reference

         23       Consent of PricewaterhouseCoopers LLP**

                                      18

<PAGE>
<PAGE>

         31.1     Certification of Chief Executive Officer pursuant to Rule
                  13a-14(a) under the Securities Exchange Act of 1934, as
                  amended is filed herewith

         31.2     Certification of Chief Financial Officer pursuant to Rule
                  13a-14(a) under the Securities Exchange Act of 1934, as
                  amended is filed herewith

         32.1     Certification of Chief Executive Officer pursuant to 18
                  U.S.C. Section 1350, as adopted pursuant to Section 906 of
                  the Sarbanes-Oxley Act of 2002 is filed herewith

         32.2     Certification of Chief Financial Officer pursuant to 18
                  U.S.C. Section 1350, as adopted pursuant to Section 906 of
                  the Sarbanes-Oxley Act of 2002 is filed herewith


<FN>
-------------------
*   Management compensatory plan or arrangement
** Previously filed






                                      19