Exhibit 5.1

                                                     August 15, 2001

United Rentals, Inc.
Five Greenwich Office Park
Greenwich, Connecticut 06830

Re:  Registration Statement on Form S-3, Registration No. 333-64662
     Relating to 10,350,000 Shares of Common Stock

Gentlemen:

     You have requested our opinion in connection with the above-referenced
registration statement (the "Registration Statement"), relating to up to
10,350,000 shares of Common Stock, par value $.01 per share, of United Rentals,
Inc. (the "Company") that the Registration Statement contemplates will be sold
by a selling stockholder.

     We have reviewed copies of the Amended and Restated Certificate of
Incorporation of the Company (including amendments thereto), the By-laws of the
Company, the Registration Statement and exhibits thereto and have examined such
corporate documents and records and other certificates, and have made such
investigations of law, as we have deemed necessary in order to render the
opinion hereinafter set forth. As to certain questions of fact material to our
opinion, we have relied upon the certificate of an officer of the Company and
upon certificates of public officials.

     Based upon and subject to the foregoing, we are of the opinion that the
10,350,000 shares of Common Stock of the Company that are being offered by the
selling stockholder have been duly authorized and are validly issued, fully paid
and non-assessable.

     We hereby consent to the reference to us under the caption "Legal Matters"
in the Registration Statement and to the use of this opinion as an exhibit to
the Registration Statement. In giving this consent, we do not hereby admit that
we come within the category of persons whose consent is required under Section 7
of the Securities Act of 1933, as amended, or the rules and regulations of the
Securities and Exchange Commission thereunder.


                                             Very truly yours,

                                         /s/ Ehrenreich Eilenberg & Krause LLP