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                                                                       EXHIBIT 5

                       [Letterhead of Baker Botts L.L.P.]

                                                               February 16, 2001

Carrizo Oil & Gas, Inc.
14701 St. Mary's Lane, Suite 800
Houston, Texas  77079

Ladies and Gentlemen:

          As set forth in the Registration Statement on Form S-8 (the
"Registration Statement") to be filed by Carrizo Oil & Gas, Inc., a Texas
corporation (the "Company"), with the Securities and Exchange Commission under
the Securities Act of 1933, as amended, relating to 500,000 shares (the
"Shares") of common stock of the Company, par value $0.01 per share (the "Common
Stock"), that may be issued pursuant to the terms of the Incentive Plan of
Carrizo Oil & Gas, Inc. (the "Incentive Plan"), certain legal matters in
connection with the Shares are being passed upon for the Company by us. At your
request, this opinion is being furnished to you for filing as Exhibit 5 to the
Registration Statement.

          In our capacity as your counsel in the connection referred to above,
we have examined the Company's Amended and Restated Articles of
Incorporation and the Amended and Restated Bylaws, each as amended to date, and
the originals, or copies certified or otherwise identified, of corporate records
of the Company, certificates of public officials and of representatives of the
Company, statutes and other instruments and documents as a basis for the
opinions hereinafter expressed. In giving such opinions, we have relied upon
certificates of officers of the Company with respect to the accuracy of the
material factual matters contained in such certificates.

          We have assumed all signatures on all documents examined by us are
genuine, that all documents submitted to us as originals are accurate and
complete, that all documents submitted to us as copies are true and correct
copies of the originals thereof and that all information submitted to us was
accurate and complete. In addition, we have assumed for purposes of paragraph 2
below that the consideration received by the Company for the Shares will be not
less than the par value of the Shares.

          On the basis of the foregoing, and subject to the assumptions,

               1.    The  Company is a  corporation duly organized
          and validly existing in good standing under the laws of the
          State of Texas.

               2.    Upon the issuance and sale of shares of Common
          Stock pursuant to the provisions of the Incentive Plan for
          consideration fixed by the Board of Directors or the
          Compensation Committee of the Board of Directors, such shares
          of Common Stock will be duly authorized by all necessary
          corporate action on the part of the Company, validly issued,
          fully paid and nonassessable.

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

                                              Very truly yours,

                                              /s/ BAKER BOTTS L.L.P.