Exhibit 5.01


                                        May 14, 2002


Brooks Automation, Inc.
15 Elizabeth Drive
Chelmsford, MA  01824

         RE: Brooks Automation, Inc. Registration Statement on Form S-8

Ladies and Gentlemen:

         We are general counsel to Brooks Automation, Inc., a Delaware
corporation (the "Company"). We have been asked to deliver this opinion in
connection with the preparation and filing with the Securities and Exchange
Commission under the Securities Act of 1933, as amended (the "Act"), of a
Registration Statement on Form S-8 (the "Registration Statement") relating to
3,318,809 shares of the Company's Common Stock, $.01 par value (the "Shares")
and 3,318,809 preferred share purchase rights (the "Rights").

         The Shares are issuable upon exercise of options granted pursuant to
the PRI option plans listed in items 5 through 11 below (collectively, the
"Plans") prior to the effective time of the merger of Pontiac Acquisition Corp.
into PRI Automation, Inc. (the "Merger"). The 3,318,809 Rights being registered
pursuant to the Registration Statement represent one Right that may be issued in
connection with each of the Shares issuable upon exercise of options granted
under the Plans.

         In connection with this opinion, we have examined the originals or
copies, certified or otherwise identified to our satisfaction, of the following
documents (collectively, the "Documents"):

               1.   A copy of the Certificate of Incorporation, as amended, of
                    the Company as in effect on the date hereof;

               2.   A copy of the By-Laws of the Company as in effect on the
                    date hereof;

               3.   The corporate minute books or other records of the Company
                    relating to the proceedings of stockholders and directors of
                    the Company;

               4.   Amended and Restated Agreement and Plan of Merger, dated as
                    of December 18, 2001, among Brooks Automation, Inc., Pontiac
                    Acquisition Corp., and PRI Automation, Inc. (the "Merger
                    Agreement");

               5.   PRI Automation, Inc. 2000 Stock Option Plan;

               6.   PRI Automation, Inc. 1997 Non-Incentive Stock Option Plan;

               7.   PRI Automation, Inc. 1994 Incentive and Non-Qualified Stock
                    Option Plan;



               8.   Commotion Technology, Inc. 2000 Flexible Stock Incentive
                    Plan;

               9.   Promis Systems Corporation Ltd. Amended and Restated Stock
                    Option Plan;

               10.  Non-Qualified Stock Option Granted by PRI Automation, Inc.
                    to Mark Johnston;

               11.  The Equipe Technologies Non-Statutory Stock Options;

               12.  The Company's Stockholder Rights Agreement dated July 23,
                    1997 (the "Rights Agreement"); and

               13.  The Registration Statement.

         For purposes of this opinion, we have assumed without any
investigation: (1) the legal capacity of each natural person; (2) the
genuineness of each signature; (3) the completeness of each document submitted
to us as an original and the conformity with the original of each document
submitted to us an original and the conformity with the original of each
document submitted to us as a copy; and (4) the completeness, accuracy and
proper indexing of all governmental records.

         We have not, except as specifically noted herein, made any independent
review or investigation of orders, judgments, rules or other regulations or
decrees by which the Company or any of its property may be bound. Nor have we
made any independent investigation as to the existence of actions, suits,
investigations or proceedings, if any, pending or threatened against the
Company.

         Our opinions contained herein are limited to the laws of The
Commonwealth of Massachusetts, the General Corporation Law of the State of
Delaware, including the statutory provisions, all applicable provisions of the
Delaware Constitution, and reported judicial decisions interpreting these laws,
and the federal law of the United States of America.

         Our opinion hereafter expressed is based solely upon: (1) our review of
the Documents; (2) discussions with those of our attorneys who have devoted
substantive attention to the matters contained herein; and (3) such review of
published sources of law as we have deemed necessary.

         Based upon and subject to the foregoing, we are of the opinion that (i)
the Shares have been duly authorized and, when issued in accordance with the
terms of the Plans after consummation of the Merger, the Shares will be validly
issued, fully paid and nonassessable and (ii) the Rights have been duly
authorized and, when issued in accordance with the terms of the Rights Agreement
and with the terms of the Plans after consummation of the Merger, the Rights
will be validly issued, fully paid and nonassessable.

         We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement and to the reference to our firm wherever it appears in
the Registration Statement.

                                        Very truly yours,


                                        BROWN RUDNICK BERLACK ISRAELS LLP

                                        /s/  BROWN RUDNICK BERLACK ISRAELS LLP