[HAYNES AND BOONE LETTERHEAD]
                                                                     Exhibit 5.1

                                August 17, 2001

VAALCO Energy, Inc.
4600 Post Oak Place, Suite 309
Houston, Texas  77027

Gentlemen:

     We have acted as counsel to VAALCO Energy, Inc, a Delaware corporation (the
"Company"), in connection with the preparation of the Registration Statement on
Form S-8 (the "Registration Statement") relating to the registration of
4,000,000 shares of the Company's common stock, par value $0.10 per share (the
"Common Stock"), that may be issued pursuant to the terms of the Company's 1996
Stock Incentive Plan (the "Plan").

     In connection therewith, we have examined (i) the Certificate of
Incorporation and the Bylaws of the Company, each as amended; (ii) the Plan and
(iii) such other documents, corporate records, certificates and other
instruments as we have deemed necessary for the expression of the opinions
contained herein.

     In making the foregoing examination, we have assumed the genuineness of all
signatures and the authenticity of all documents submitted to us as originals,
and the conformity to original documents of all documents submitted to us as
certified or photostatic copies.  Furthermore, we have assumed that prices paid
for shares of Common Stock will equal or exceed the par value per share of the
Common Stock.  As to questions of fact material to this opinion, where such
facts have not been independently established, and as to the content and form of
the Certificate of Incorporation (as amended), Bylaws (as amended), Plan,
minutes, records, resolutions and other documents or writings of the Company, we
have relied, to the extent we deem reasonably appropriate, upon representations
or certificates of officers or directors of the Company and upon documents,
records and instruments furnished to us by the Company, without independent
check or verification of their accuracy.

     Based upon the foregoing, and having due regard for such legal
considerations as we deem relevant, we are of the opinion that the 4,000,000
shares of Common Stock covered by the Registration Statement, which may be
issued from time to time pursuant to the purchase of shares of Common Stock in
accordance with the terms of the Plan, have been duly authorized for issuance by
the Company, and when so issued in accordance with the respective terms and
conditions of the Plan, will be validly issued, fully paid and nonassessable.

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

                                        Very truly yours,

                                        /s/ Haynes and Boone, LLP

                                        Haynes and Boone, L.L.P.