Exhibit 5.1

                       [LETTERHEAD OF COOLEY GODWARD LLP]

February 9, 2000

Blue Martini Software, Inc.
2600 Campus Drive
San Mateo, CA 94403

Re: Form S-8

Ladies and Gentlemen:

   You have requested our opinion with respect to certain matters in connection
with the filing by Blue Martini Software, Inc. (the "Company") of a
Registration Statement on Form S-8 (the "Registration Statement") with the
Securities and Exchange Commission covering the offering of up to (i)
10,378,225 shares of the Company's Common Stock, $.001 par value (the
"Shares"), issuable upon the exercise of stock options granted or to be granted
under the Company's 2000 Equity Incentive Plan (the "2000 Equity Incentive
Plan"), (ii) 1,724,102 shares of the Company's Common Stock, $.001 par value,
issuable upon the purchase of shares under the Company's 2000 Employee Stock
Purchase Plan (the "2000 ESPP") and (iii) 172,410 shares of the Company's
Common Stock, $.001 par value, issuable upon the exercise of stock options
granted or to be granted under the Company's 2000 Non-Employee Directors' Stock
Option Plan (the "Directors' Plan") (together the "Shares").

   In connection with this opinion, we have examined the Registration
Statement, the Company's Amended and Restated Certificate of Incorporation and
Bylaws, and such other documents, records, certificates, memoranda and other
instruments as we deem necessary as a basis for this opinion. We have assumed
the genuineness and authenticity of all documents submitted to us as originals,
the conformity to originals of all documents submitted to us as copies thereof
and the due execution and delivery of all documents where due execution and
delivery are a prerequisite to the effectiveness thereof.

   Our opinion is expressed only with respect to the federal laws of the United
States of America, the General Corporation Law of the State of Delaware and the
laws of the State of California. We express no opinion as to whether the laws
of any particular jurisdiction other than those identified above are applicable
to the subject matter hereof.

   On the basis of the foregoing, and in reliance thereon, we are of the
opinion that the Shares, when sold and issued in accordance with the 2000
Equity Incentive Plan, the 2000 ESPP, the Directors' Plan and the Registration
Statement, will be validly issued, fully paid, and nonassessable.

   We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

Cooley Godward LLP


          /s/ Mark P. Tanoury
By: _________________________________
            Mark P. Tanoury