Exhibit 4

July ___, 2001


Capital Environmental Resource Inc.
1005 Skyview Drive
Burlington, Ontario L7P 5B1


Dear Sirs:

         The undersigned, [NAME OF INVESTOR], along with other investors, is a
party to a Subscription Agreement with Capital Environmental Resource Inc (the
"Company") dated July ___, 2001 (the "Subscription Agreement") pursuant to which
the undersigned will acquire shares of common stock of the Company ("Common
Stock"). The undersigned understands that the Company proposes to enter into (i)
a Fifth Amendment and Waiver and Consent (the "Credit Agreement Fifth
Amendment") to the Second Amended and Restated Credit Agreement, dated as of
November 26, 1999 (the "Credit Agreement"), by and among the Company, the
lenders named therein (the "Credit Agreement Lenders"), Canadian Imperial Bank
of Commerce in its capacity as Syndication Agent (the "Syndication Agent"), Bank
of America N.A. in its capacity as U.S. Agent (the "U.S. Agent"), and Bank of
America Canada in its capacity as Canadian Agent (the "Canadian Agent") and (ii)
a Fifth Amendment and Waiver to the Term Loan Agreement (the "Term Loan Fifth
Amendment") to the Term Loan Agreement, dated as of November 26, 1999 (the "Term
Loan Agreement"), by and among the Company, the lenders named therein (the "Term
Loan Lenders") and Bank of America, N.A. in its capacity as Agent (the "Term
Loan Agent")

         To induce the Credit Agreement Lenders, Syndication Agent, U.S. Agent
and Canadian Agent to enter into the Credit Agreement Fifth Amendment, to induce
the Term Loan Lenders and the Term Loan Agent to enter into the Term Loan Fifth
Amendment and as a condition to closing under the Subscription Agreement, the
undersigned, during the period commencing on the date hereof and ending on the
earlier of (a) May 31, 2002, or (b) payment in full of all obligations of the
Company under the Credit Agreement and the Term Loan Agreement, each as amended
(the "Restricted Period"):






           (i) agrees not to (x) offer, pledge, sell, contract to sell, sell any
option or contract to purchase, purchase any option or contract to sell, grant
any option, right or warrant to purchase, or otherwise transfer or dispose of,
directly or indirectly, any shares of Common Stock owned by the undersigned as
of the date hereof or acquired by the undersigned pursuant to the Subscription
Agreement (the "Subject Securities") or (y) enter into any swap or other
arrangement that transfers all or a portion of the economic consequences
associated with the ownership of any Subject Securities (regardless of whether
any of the transactions described in clause (x) or (y) is to be settled by the
delivery of Common Stock, in cash or otherwise), without the prior written
consent of the Company; provided, however, that the undersigned may transfer or
assign Subject Securities at any time to (a) the spouse or children of the
undersigned or of a person controlling the undersigned or to a trust of which
the undersigned or a person controlling the undersigned is the settlor and a
trustee for the benefit of such spouse or children, provided that any such trust
does not require or permit distribution of such Subject Securities during the
Restricted Period, (b) entities or persons that hold limited partnership
interests in the undersigned or (c) any entity that controls, is controlled by
or is under common control with the undersigned, if such transferees shall have
executed and delivered a letter to the Company with respect to the transferred
Subject Securities in substantially the form of this letter, ("Permitted
Transferees"); and

          (ii) authorizes the Company to cause the transfer agent to decline to
transfer and/or to note stop transfer restrictions on the transfer books and
records of the Company with respect to any Subject Securities for which the
undersigned is the record holder and, in the case of any Subject Securities for
which the undersigned is the beneficial but not the record holder, agrees to
cause the record holder to cause the transfer agent to decline to transfer
and/or to note stop transfer restrictions on such books and records with respect
to such Subject Securities; provided, however, that transfers to Permitted
Transferees shall be permitted.

           The parties hereto agree that the terms and conditions of this letter
agreement may not be amended or waived or otherwise modified in any respect
without the prior written consent of the U.S. Agent and the Term Loan Agent.

         The undersigned hereby represents and warrants that the undersigned has
full power and authority to enter into the agreements set forth herein, and
that, upon request, the undersigned will execute any additional documents
necessary or desirable in connection with the enforcement hereof. All authority
herein conferred or agreed to be conferred shall survive the death or incapacity
of the undersigned and any obligations of the undersigned shall be binding upon
the heirs, personal representatives, successors, and assigns of the undersigned.

                                               Very truly yours,


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

(Name - Please Type)





(Address)


(Social Security or Taxpayer Identification No.)


Number of shares of Common Stock
    owned as of the date hereof:
                                                     ---------------------------

Certificate Numbers:





Number of shares of Common Stock to be acquired
     pursuant to the Subscription Agreement:
                                                     ---------------------------



Acknowledged and Agreed:

Capital Environmental Resource Inc.



By:
   ----------------------------------------------
Name:
Title: