EXHIBIT 5.1

              [Letterhead of LeBoeuf, Lamb, Greene & MacRae, L.L.P]

                                                     June 11, 2003

Public Service Company of Colorado
1225 17th Street
Denver, Colorado  80202

Ladies and Gentlemen:

                  We have acted as counsel for Public Service Company of
Colorado, a Colorado corporation (the "Company"), in connection with the
preparation and filing with the Securities and Exchange Commission (the
"Commission") under the Securities Act of 1933, as amended (the "Securities
Act"), of a Registration Statement on Form S-4 (the "Registration Statement"),
relating to the offer to exchange 4.875% First Collateral Trust Bonds, Series
No. 12 due 2013 (the "Bonds") for any and all outstanding 4.875% First
Collateral Trust Bonds, Series No. 11 due 2013 (the "Original Bonds").

                  The Bonds will be issued pursuant to an Indenture dated as of
October 1, 1993 the ("Bond Indenture"), between the Company and U.S. Bank Trust
National Association, as successor trustee thereunder (the "Bond Trustee").

                  In connection with this opinion, we have examined a copy of
the Registration Statement and such corporate records, certificates and other
documents as we have considered necessary for the purposes of this opinion. In
such examination, we have assumed the genuineness of all signatures, the
authenticity of all documents submitted to us as originals, the conformity to
the original documents of all documents submitted to us as copies and the
authenticity of the originals of such latter documents. As to any facts material
to our opinion, we have, when relevant facts were not independently established,
relied upon the aforesaid records, certificates and documents.



Public Service Company of Colorado
June 11,2003
Page 2

                  Based on the foregoing examination, and subject to the
qualifications and limitations contained herein, we are of the opinion that:

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

         2.       When (i) the Registration Statement, as finally amended
                  (including any necessary post-effective amendments), has
                  become effective under the Securities Act; and (ii) all
                  orders, consents or other authorizations of the Public
                  Utilities Commission of the State of Colorado (the "CPUC")
                  required for the valid issuance and sale of the Bonds have
                  been obtained, no further authorization, consent or approval
                  by any regulatory authority will be required for the valid
                  issuance and sale of the Bonds.

         3.       When a Board Resolution or Officer's Certificate within the
                  meaning of the Bond Indenture has been issued or a
                  supplemental indenture entered into, in accordance with the
                  Bond Indenture detailing the establishment of the Bonds, such
                  Bonds will have been duly authorized by the Company.

         4.       Upon the execution and filing with the Bond Trustee of the
                  proper papers with respect to the Bonds, the Bonds will be
                  issuable under the terms of the Bond Indenture.

         5.       When the Bonds have been duly executed, authenticated and
                  delivered in accordance with the corporate and governmental
                  authorizations and the instruments referred to above and the
                  Original Bonds have been validly tendered and not withdrawn
                  prior to the expiration date of the exchange offer, the Bonds
                  will be legally issued and binding obligations of the Company
                  and will be entitled to the benefits of the Bond Indenture on
                  a parity with the securities of other series which may be
                  thereafter issued pursuant to the terms of such indenture
                  (subject to bankruptcy, insolvency, reorganization,
                  moratorium, fraudulent conveyance or other similar laws
                  affecting the enforcement of creditors' rights generally and
                  to general principles of equity, regardless of whether such
                  principles are considered in a proceeding in equity or at
                  law).

                  We express no opinion as to the application of the securities
or blue sky laws of the several states to the sale of the securities to be
registered pursuant to the Registration Statement.

                  Our opinion expressed above is limited to the laws of the
State of New York and the State of Colorado, and the federal laws of the United
States of America.




Public Service Company of Colorado
June 11,2003
Page 3


                  We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement and the use of our name under the headings
"Description of the Exchange First Collateral Trust Bonds" and "Description of
the 1939 Mortgage" in the prospectus forming a part of the Registration
Statement.

                                    Very truly yours

                                    /S/ LeBoeuf, Lamb, Greene & MacRae, L.L.P