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                                                                     EXHIBIT 5.1

                                December 12, 2005

Genesis Energy, L.P.
500 Dallas, Suite 2500
Houston, Texas 77002

     Re: Genesis Energy, L.P.

Ladies and Gentlemen:

     We have acted as counsel to Genesis Energy, L.P., a Delaware limited
partnership (the "PARTNERSHIP"), in connection with the proposed offering and
sale by the Partnership of up to 4,140,000 common units representing limited
partner interests of the Partnership (the "COMMON UNITS"), including an
over-allotment option to purchase an additional 540,000 units. We refer to the
registration statement on Form S-3, as amended (Registration No. 333-126482)
filed on July 8, 2005 by the Partnership with the Securities and Exchange
Commission (the "Commission") under the Securities Act of 1933, as amended (the
"ACT"), and Amendment No. 1 thereto filed with the Commission on August 30, 2005
(the "REGISTRATION STATEMENT"). A prospectus supplement dated December 8, 2005
(the "PROSPECTUS"), which together with the prospectus filed with the
Registration Statement shall constitute part of the Prospectus, has been filed
pursuant to Rule 424(b) promulgated under the Act. Capitalized terms not defined
herein shall have the meanings ascribed to them in the Underwriting Agreement
dated December 7, 2005 (the "UNDERWRITING AGREEMENT") relating to the offer and
sale of the Common Units. We have examined originals or certified copies of such
corporate records of the Partnership and other certificates and documents of
officials of the Partnership, public officials and others as we have deemed
appropriate for purposes of this letter. We have assumed the genuineness of all
signatures, the authenticity of all documents submitted to us as originals, and
the conformity to authentic original documents of all copies submitted to us as
conformed and certified or reproduced copies.

     Based upon the foregoing and subject to the assumptions, exceptions,
qualifications and limitations set forth hereinafter, we are of the opinion
that:

     1. When the Common Units have been issued and delivered in accordance with
the terms of the Underwriting Agreement and upon payment of the consideration
therefor provided for therein, (a) such Common Units will be duly authorized and
validly issued and (b) on the assumption that the holder of such Common Units is
not also a general partner of the Partnership and does not participate in the
control of the Partnership's business, the Common Units will be fully paid and
non-assessable.

     The opinions and other matters in this letter are qualified in their
entirety and subject to the following:

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     A.   We have assumed that the Common Units will be issued and sold in the
          manner stated in the Registration Statement and the Prospectus and in
          accordance with the terms of the Underwriting Agreement.

     B.   The opinion set forth in paragraph 1(b) is subject to the
          qualification that (i) under Section 17-303(a) of the Delaware Revised
          Uniform Limited Partnership Act (the "DELAWARE ACT"), a limited
          partner who participates in the "control," within the meaning of the
          Delaware Act, of the business of a partnership or takes action which
          constitutes "control" may be held personally liable for such
          partnership's obligations under the Delaware Act to the same extent as
          a general partner and (ii) under Section 17-607 of the Delaware Act, a
          limited partner who (x) receives a distribution that, at the time of
          distribution and after giving effect to the distribution, causes all
          liabilities of the Partnership, other than liabilities to partners on
          account of their partnership interests and non-recourse liabilities,
          to exceed the fair value of the assets of the limited partnership
          (except the fair value of property subject to a liability for which
          the recourse of creditors is limited, which property shall be included
          in the assets of the limited partnership only to the extent that the
          fair value of such property exceeds such liability) and (y) knew at
          the time of such distribution that the distribution was in violation
          of the Delaware Act shall be liable to the limited partnership for the
          amount of the distribution for three years from the date of the
          distribution.

     C.   We express no opinion as to the laws of any jurisdiction other than
          any published constitutions, treaties, laws, rules or regulations or
          judicial or administrative decisions ("LAWS") of (i) the federal Laws
          of the United States and (ii) the Revised Uniform Limited Partnership
          Act of the State of Delaware and (iii) Delaware corporation laws.

     D.   The matters expressed in this letter are subject to and qualified and
          limited by (i) applicable bankruptcy, insolvency, fraudulent transfer
          and conveyance, reorganization, moratorium and similar laws affecting
          creditors' rights and remedies generally, (ii) general principles of
          equity, including principles of commercial reasonableness, good faith
          and fair dealing (regardless of whether enforcement is sought in a
          proceeding at law or in equity), (iii) commercial reasonableness and
          unconscionability and an implied covenant of good faith and fair
          dealing, (iv) the power of the courts to award damages in lieu of
          equitable remedies, (v) securities Laws and public policy underlying
          such Laws with respect to rights to indemnification and contribution
          and (vi) limitations on the waiver of rights under usury law.

     E.   This law firm is a registered limited liability partnership organized
          under the laws of the state of Texas.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of our name in the Prospectus under the
caption "Legal Matters." In giving this consent, we do not thereby admit that we
are within the category of persons whose consent is

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required under Section 7 of the Act and the rules and regulations thereunder. We
also consent to your filing copies of this opinion as an exhibit to the
Registration Statement.

                                   Very truly yours,


                                   /s/ AKIN, GUMP, STRAUSS, HAUER & FELD, L.L.P.
