<PAGE>


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                            CECO ENVIRONMENTAL CORP.
         (Exact name of registrant as specified in its charter)

                 New York                           13-2566064
      (State or other jurisdiction               (I.R.S. Employer
             of incorporation)                Identification Number)

         505 University Avenue,                      M5G 1X3
        Toronto, Ontario CANADA                    (Zip Code)
                     (Address of Principal Executive Office)

                            CECO Environmental Corp.
                 CECO Environmental Corp. 1997 Stock Option Plan
                            (Full Title of the Plan)

                              Leslie J. Weiss, Esq.
                          Sugar, Friedberg & Felsenthal
                       30 North LaSalle Street, Suite 2600
                             Chicago, Illinois 60602
                     (Name and address of agent for service)

                                 (312) 704-9400
          (Telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale to the public: As soon as
Practicable After Registration Statement Becomes Effective.



<PAGE>




                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
                                                       Proposed               Proposed
       Title of                                        Maximum                 Maximum
  Securities to be            Amount to be          Offering Price            Aggregate                  Amount of
     Registered                Registered            Per Share (1)         Offering Price (1)        Registration Fee (1)
     ----------                ----------            -------------         ------------------        --------------------
<S>                            <C>                    <C>                    <C>                         <C>
Common Shares
par value $0.01
per share

                                1,500,000               $2,7031               $4,054,650                  $1,070.43
-----------------------------------------------------------------------------------------------------------------------------------

Total                           1,500,000               $2,7031               $4,054,650                  $1,070.43
-----------------------------------------------------------------------------------------------------------------------------------
</TABLE>



         (1) Based upon the closing price as reported by NASDAQ on March 22,
2000, and estimated in the manner specified by Rule 457(c)under the Securities
Act of 1933, solely for purposes of calculating the amount of registration fee.


<PAGE>



                                     PART I

                INFORMATION REQUIRED IN SECTION 10(A) PROSPECTUS

Item 1.           Plan Information.

                  The document(s) containing the information specified in part I
of Form S-8 will be sent or given to the employees as specified by Rule
428(b)(1) of the Securities Act of 1933, as amended (the "Security Act"). Such
documents are not required to be and are not being filed with the SEC or
included in this Form S-8 (by incorporation by reference or otherwise) in
accordance with the rules and regulations of the Securities and Exchange
Commission (the "SEC"). These documents and the documents incorporated by
reference into this Registration Statement pursuant to Item 3 of Part II of this
Registration Statement, taken together, constitute a prospectus that meets the
requirements of Section 10(a) of the Securities Act.

Item 2.           Registrant Information and Employee Plan Annual Information.


                  Upon written or oral request, any of the documents
incorporated by reference in Item 3 of Part II of this Registration Statement
(which documents are incorporated by reference in this Section 10(a)
Prospectus), other documents required to be delivered to eligible employees
pursuant to Rule 428(b) or additional information about the CECO Environmental
Corp. 1997 Stock Option Plan and its administrators are available without charge
by contacting:

                               Marshall J. Morris
                             Chief Financial Officer
                                CECO Group, Inc.
                               3120 Forrer Street
                             Cincinnati, Ohio 45209
                                 (513) 458-2666


                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 3.           Incorporation of Documents by Reference.

                  The following documents filed with the Commission pursuant to
the Securities Exchange Act of 1934 are incorporated by reference into this
Registration Statement.


<PAGE>


         a. The Company's Annual Report on Form 10-KSB for the fiscal year ended
 December 31, 1998.

         b. The description of the Company's Common Stock, $0.01 par value,
contained in the Company's registration statement on Form 10 filed pursuant to
Section 12(g) of the Securities Exchange Act of 1934 on April 27, 1973, which
was declared effective on September 28, 1973, including any subsequent amendment
or any report or other filing with the Securities and Exchange Commission
updating such description.

         c. All reports subsequently filed by the Registrant pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934 since
the end of the fiscal year covered by the Company's document referred to in (a)
above, shall be deemed to be incorporated by reference in the Registration
Statement and to be part thereof from the date of filing of such documents.

Item 4.           Description of Securities.

                  Not Applicable.

Item 5.           Interest of Named Experts and Counsel.

                  The validity of the Shares offered hereby will be passed upon
for the Company by Sugar, Friedberg & Felsenthal, 30 North LaSalle Street, Suite
2600, Chicago, Illinois 60602.

Item 6.           Indemnification of Officers and Directors.

                  The Company's By-laws provide that the Company shall indemnify
any person made, or threatened to be made, a party to an action or proceeding,
whether civil or criminal or investigative (a "proceeding"), including an action
by or in the right of the Company or any other corporation of any type or kind,
domestic or foreign, or any partnership, joint venture, trust, employee benefit
plan or other enterprise, which any director or officer of the Company served in
any capacity at the request of the Company, by reason of the fact that he, his
testator or interstate, was a director or officer of the Company, or served such
other corporation, partnership, joint venture, trust, employee benefit plan or
other enterprise in any capacity, against judgment, fines, amounts paid in
settlement and reasonable expenses, including attorney's fees actually and
necessarily incurred as a result of such proceeding, or any appeal therein, if
such director or officer acted, in good faith, for a purpose which he reasonably
believed to be in, or in the case of service for any other corporation or any
partnership, joint venture, trust, employee benefit plan or other enterprise,
not opposed to, the best interests of the Company and, in criminal proceedings,
in addition, had no reasonable cause to believe that his conduct was unlawful.

         Any determination as to whether a person has met an applicable standard
of conduct shall be made in accordance with the provisions of the Business
Corporation Law of the State of New York.


<PAGE>

         No indemnification shall be made to or on behalf of any person if a
judgment or other final adjudication adverse to such person establishes that his
acts were committed in bad faith or were the result of active and deliberate
dishonesty and were material to the cause of action so adjudicated, or that he
personally gained in fact a financial profit or other advantage to which he was
not legally entitled.

         The Company's indemnification provisions shall be enforced to the
fullest extent permitted under law.

Item 7.  Exemption from Registration Claimed.

                  Not Applicable.

Item 8.  Exhibits.

         Exhibit
         Number            Description
         ------            -----------

           4               CECO Environmental Corp. 1997 Stock Option Plan
           5               Opinion of Counsel regarding legality
        23.1               Consent of Independent Public Accountant
        23.2               Consent of Counsel (Included in Exhibit 5)
        24.                Power of Attorney (Contained within Signature Page)

Item 9.           Undertakings.

         (1)      The undersigned Registrant hereby undertakes:

                  (a) To file, during any period in which offers or sales are
being made, a post-effective amendment to this Registration Statement: To
include any material information with respect to the plan of distribution not
previously disclosed in the Registration Statement or any material change to
such information in the Registration Statement;

                  (b) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof;

                  (c) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

         (2) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 that is incorporated by reference in the Registration
Statement shall be deemed to be a new registration statement relating to the
securities offered therein and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

         (3) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the even that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.


<PAGE>


                                   SIGNATURES
                                   ----------

                  Pursuant to the requirements of the Securities Act of 1933, as
amended the Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Toronto, Province of Ontario, on this 24th day
of March, 2000.



                                                   CECO ENVIRONMENTAL CORP.

                                                   By: /s/ Phillip DeZwirek
                                                       -------------------------
                                                       Phillip DeZwirek
                                                       Chief Executive Officer,
                                                       Director


                                POWER OF ATTORNEY

                  KNOW ALL MEN BY THESE PRESENTS, that each person whose
signature appears below constitutes and appoints Phillip DeZwirek, his or her
attorney-in-fact, for him or her in any and all capacities, to sign any
amendments to this Registration Statement, and to file the same, with exhibits
thereto, and other documents in connection therewith, with the Securities and
Exchange Commission, hereby ratifying and confirming all that said
attorney-in-fact, or his substitute, may do or cause to be done by virtue
hereof.

                  Pursuant to the requirements of the Securities Act of 1933, as
amended this Registration Statement has been signed by the following persons in
the capacities and on the dates indicated.


Date: March 24, 2000                        /s/ Phillip DeZwirek
                                            --------------------
                                                Phillip DeZwirek, Chief
                                                Executive Officer, Director

Date: March 24, 2000                        /s/ Marshall J. Morris
                                            ----------------------
                                                Marshall Morris, Chief
                                                Financial Officer

Date: March 24, 2000                        /s/ Jason Louis DeZwirek
                                            ------------------------
                                                Jason Louis DeZwirek, Director

Date: March 24, 2000                        /s/ Josephine Grivas
                                            --------------------
                                                Josephine Grivas, Director


Date: March 24, 2000                        /s/ Donald Wright
                                            -----------------
                                                Donald Wright, Director


<PAGE>


                                  EXHIBIT INDEX

         Exhibit                                                          Page
         Number            Document                                      Number
         ------            --------                                      ------


          4        CECO Environmental Corp. 1997
                           Stock Option Plan and Amendment                  9

          5        Opinion of Counsel regarding legality                   19

          23.1     Consent of Margolis & Company P.C.                      20

          23.2     Consent of Counsel (Included in                         19
                           Exhibit 5)


          24.      Power of Attorney (Contained with                        7
                           Signature Page)
[{"type": "S-8", "sequence": "1", "description": "S-8", "secsgml_size_bytes": 15628}]
{"company-data": {"conformed-name": "CECO ENVIRONMENTAL CORP", "cik": "0000003197", "assigned-sic": "3564", "irs-number": "132566064", "state-of-incorporation": "NY", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-33270", "film-number": "578515"}, "business-address": {"street1": "505 UNIVERSITY AVE", "street2": "STE 1400", "city": "TORONTO ONTARIO MSG", "state": "A6", "phone": "4165936543"}, "mail-address": {"street1": "111 ELIZABETH STREET SUITE 600", "city": "TORONTO ONTARIO", "state": "A6"}, "former-company": [{"former-conformed-name": "API ENTERPRISES INC", "date-changed": "19920703"}, {"former-conformed-name": "ALARM PRODUCTS INTERNATIONAL INC", "date-changed": "19851210"}]}
SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                            CECO ENVIRONMENTAL CORP.
         (Exact name of registrant as specified in its charter)

                 New York                           13-2566064
      (State or other jurisdiction               (I.R.S. Employer
             of incorporation)                Identification Number)

         505 University Avenue,                      M5G 1X3
        Toronto, Ontario CANADA                    (Zip Code)
                     (Address of Principal Executive Office)

                            CECO Environmental Corp.
                 CECO Environmental Corp. 1997 Stock Option Plan
                            (Full Title of the Plan)

                              Leslie J. Weiss, Esq.
                          Sugar, Friedberg & Felsenthal
                       30 North LaSalle Street, Suite 2600
                             Chicago, Illinois 60602
                     (Name and address of agent for service)

                                 (312) 704-9400
          (Telephone number, including area code, of agent for service)

Approximate date of commencement of proposed sale to the public: As soon as
Practicable After Registration Statement Becomes Effective.
CALCULATION OF REGISTRATION FEE
-----------------------------------------------------------------------------------------------------------------------------------
                                                       Proposed               Proposed
       Title of                                        Maximum                 Maximum
  Securities to be            Amount to be          Offering Price            Aggregate                  Amount of
     Registered                Registered            Per Share (1)         Offering Price (1)        Registration Fee (1)
     ----------                ----------            -------------         ------------------        --------------------
Common Shares
par value $0.01
per share

                                1,500,000               $2,7031               $4,054,650                  $1,070.43
-----------------------------------------------------------------------------------------------------------------------------------

Total                           1,500,000               $2,7031               $4,054,650                  $1,070.43
-----------------------------------------------------------------------------------------------------------------------------------
(1) Based upon the closing price as reported by NASDAQ on March 22,
2000, and estimated in the manner specified by Rule 457(c)under the Securities
Act of 1933, solely for purposes of calculating the amount of registration fee.
PART I

                INFORMATION REQUIRED IN SECTION 10(A) PROSPECTUS

Item 1.           Plan Information.

                  The document(s) containing the information specified in part I
of Form S-8 will be sent or given to the employees as specified by Rule
428(b)(1) of the Securities Act of 1933, as amended (the "Security Act"). Such
documents are not required to be and are not being filed with the SEC or
included in this Form S-8 (by incorporation by reference or otherwise) in
accordance with the rules and regulations of the Securities and Exchange
Commission (the "SEC"). These documents and the documents incorporated by
reference into this Registration Statement pursuant to Item 3 of Part II of this
Registration Statement, taken together, constitute a prospectus that meets the
requirements of Section 10(a) of the Securities Act.

Item 2.           Registrant Information and Employee Plan Annual Information.

                  Upon written or oral request, any of the documents
incorporated by reference in Item 3 of Part II of this Registration Statement
(which documents are incorporated by reference in this Section 10(a)
Prospectus), other documents required to be delivered to eligible employees
pursuant to Rule 428(b) or additional information about the CECO Environmental
Corp. 1997 Stock Option Plan and its administrators are available without charge
by contacting:

                               Marshall J. Morris
                             Chief Financial Officer
                                CECO Group, Inc.
                               3120 Forrer Street
                             Cincinnati, Ohio 45209
                                 (513) 458-2666

                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 3.           Incorporation of Documents by Reference.

                  The following documents filed with the Commission pursuant to
the Securities Exchange Act of 1934 are incorporated by reference into this
Registration Statement.
a. The Company's Annual Report on Form 10-KSB for the fiscal year ended
 December 31, 1998.

         b. The description of the Company's Common Stock, $0.01 par value,
contained in the Company's registration statement on Form 10 filed pursuant to
Section 12(g) of the Securities Exchange Act of 1934 on April 27, 1973, which
was declared effective on September 28, 1973, including any subsequent amendment
or any report or other filing with the Securities and Exchange Commission
updating such description.

         c. All reports subsequently filed by the Registrant pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934 since
the end of the fiscal year covered by the Company's document referred to in (a)
above, shall be deemed to be incorporated by reference in the Registration
Statement and to be part thereof from the date of filing of such documents.

Item 4.           Description of Securities.

                  Not Applicable.

Item 5.           Interest of Named Experts and Counsel.

                  The validity of the Shares offered hereby will be passed upon
for the Company by Sugar, Friedberg & Felsenthal, 30 North LaSalle Street, Suite
2600, Chicago, Illinois 60602.

Item 6.           Indemnification of Officers and Directors.

                  The Company's By-laws provide that the Company shall indemnify
any person made, or threatened to be made, a party to an action or proceeding,
whether civil or criminal or investigative (a "proceeding"), including an action
by or in the right of the Company or any other corporation of any type or kind,
domestic or foreign, or any partnership, joint venture, trust, employee benefit
plan or other enterprise, which any director or officer of the Company served in
any capacity at the request of the Company, by reason of the fact that he, his
testator or interstate, was a director or officer of the Company, or served such
other corporation, partnership, joint venture, trust, employee benefit plan or
other enterprise in any capacity, against judgment, fines, amounts paid in
settlement and reasonable expenses, including attorney's fees actually and
necessarily incurred as a result of such proceeding, or any appeal therein, if
such director or officer acted, in good faith, for a purpose which he reasonably
believed to be in, or in the case of service for any other corporation or any
partnership, joint venture, trust, employee benefit plan or other enterprise,
not opposed to, the best interests of the Company and, in criminal proceedings,
in addition, had no reasonable cause to believe that his conduct was unlawful.

         Any determination as to whether a person has met an applicable standard
of conduct shall be made in accordance with the provisions of the Business
Corporation Law of the State of New York.
No indemnification shall be made to or on behalf of any person if a
judgment or other final adjudication adverse to such person establishes that his
acts were committed in bad faith or were the result of active and deliberate
dishonesty and were material to the cause of action so adjudicated, or that he
personally gained in fact a financial profit or other advantage to which he was
not legally entitled.

         The Company's indemnification provisions shall be enforced to the
fullest extent permitted under law.

Item 7.  Exemption from Registration Claimed.

                  Not Applicable.

Item 8.  Exhibits.

         Exhibit
         Number            Description
         ------            -----------

           4               CECO Environmental Corp. 1997 Stock Option Plan
           5               Opinion of Counsel regarding legality
        23.1               Consent of Independent Public Accountant
        23.2               Consent of Counsel (Included in Exhibit 5)
        24.                Power of Attorney (Contained within Signature Page)

Item 9.           Undertakings.

         (1)      The undersigned Registrant hereby undertakes:

                  (a) To file, during any period in which offers or sales are
being made, a post-effective amendment to this Registration Statement: To
include any material information with respect to the plan of distribution not
previously disclosed in the Registration Statement or any material change to
such information in the Registration Statement;

                  (b) That, for the purpose of determining any liability under
the Securities Act of 1933, each such post-effective amendment shall be deemed
to be a new registration statement relating to the securities offered therein,
and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof;

                  (c) To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

         (2) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
Registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 that is incorporated by reference in the Registration
Statement shall be deemed to be a new registration statement relating to the
securities offered therein and the offering of such securities at that time
shall be deemed to be the initial bona fide offering thereof.

         (3) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Registrant pursuant to the foregoing provisions, or otherwise,
the Registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the even that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.
SIGNATURES
                                   ----------

                  Pursuant to the requirements of the Securities Act of 1933, as
amended the Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Toronto, Province of Ontario, on this 24th day
of March, 2000.

                                                   CECO ENVIRONMENTAL CORP.

                                                   By: /s/ Phillip DeZwirek
                                                       -------------------------
                                                       Phillip DeZwirek
                                                       Chief Executive Officer,
                                                       Director

                                POWER OF ATTORNEY

                  KNOW ALL MEN BY THESE PRESENTS, that each person whose
signature appears below constitutes and appoints Phillip DeZwirek, his or her
attorney-in-fact, for him or her in any and all capacities, to sign any
amendments to this Registration Statement, and to file the same, with exhibits
thereto, and other documents in connection therewith, with the Securities and
Exchange Commission, hereby ratifying and confirming all that said
attorney-in-fact, or his substitute, may do or cause to be done by virtue
hereof.

                  Pursuant to the requirements of the Securities Act of 1933, as
amended this Registration Statement has been signed by the following persons in
the capacities and on the dates indicated.

Date: March 24, 2000                        /s/ Phillip DeZwirek
                                            --------------------
                                                Phillip DeZwirek, Chief
                                                Executive Officer, Director

Date: March 24, 2000                        /s/ Marshall J. Morris
                                            ----------------------
                                                Marshall Morris, Chief
                                                Financial Officer

Date: March 24, 2000                        /s/ Jason Louis DeZwirek
                                            ------------------------
                                                Jason Louis DeZwirek, Director

Date: March 24, 2000                        /s/ Josephine Grivas
                                            --------------------
                                                Josephine Grivas, Director

Date: March 24, 2000                        /s/ Donald Wright
                                            -----------------
                                                Donald Wright, Director
EXHIBIT INDEX

         Exhibit                                                          Page
         Number            Document                                      Number
         ------            --------                                      ------

          4        CECO Environmental Corp. 1997
                           Stock Option Plan and Amendment                  9

          5        Opinion of Counsel regarding legality                   19

          23.1     Consent of Margolis & Company P.C.                      20

          23.2     Consent of Counsel (Included in                         19
                           Exhibit 5)

          24.      Power of Attorney (Contained with                        7
                           Signature Page)