Exhibit 8.1

ALSTON&BIRD LLP

The Atlantic Building

950 F Street, NW

Washington, DC 20004-1404

202-756-3300

Fax: 202-756-3333

www.alston.com

April 1, 2010

Duke Realty Limited Partnership

600 East 96^th Street, Suite 100

Indianapolis, IN 46240

Ladies and Gentlemen:

We have represented Duke Realty Corporation, an Indiana corporation (the “Company”), and Duke Realty Limited Partnership, an Indiana limited partnership (the “Operating Partnership”), in connection with the Operating Partnership’s issuance of the Notes. You have requested our opinion as to (i) the qualification of the Company as a real estate investment trust (“REIT”) under Sections 856 through 860 of the Internal Revenue Code of 1986, as amended (the “Code”) and (ii) the accuracy of the discussion of US federal income tax considerations contained under the caption “Federal Income Tax Considerations” in the Base Prospectus (as defined below) and in the Prospectus Supplement (as defined below).

In connection with this opinion, we have made such legal and factual inquiries as we have deemed necessary or appropriate, including examination of the Company’s Registration Statement on Form S-3 (Registration Statement No. 333-160952), filed with the Securities and Exchange Commission (the “Commission”) on July 31, 2009, which includes the Company’s base Prospectus dated July 31, 2009 (the “Base Prospectus”), and the Operating Partnership’s Prospectus Supplement dated March 25, 2010 (the “Prospectus Supplement”). In addition, you have provided us with, and we are relying upon, a certificate containing certain factual representations and covenants of an officer of the Company (the “Officer’s Certificate”) relating to, among other things, the actual and proposed operations of the Company and the entities in which it holds direct or indirect interests. For purposes of our opinion, however, we have not made an independent investigation of the facts, representations and covenants set forth in the Officer’s Certificate, the Prospectus, or in any other document. In particular, we note that the Company may engage in transactions in connection with which we have not provided legal advice, and have not reviewed, and of which we may be unaware. We have assumed and

One Atlantic Center • 1201 West Peachtree Street • Atlanta, GA 30309-3424 • 404-881-7000 • Fax: 404-881-7777

Bank of America Plaza • 101 South Tryon Street, Suite 4000 • Charlotte, NC 28280-4000 • 704-444-1000 • Fax: 704-444-1111

Chase Tower • 2200 Ross Avenue, Suite 3601 • Dallas, TX 75201-2708 • 214-922-3400 • Fax: 214-922-3899

333 South Hope Street • 16th Floor • Los Angeles, CA 90071-1410 • 213-576-1000 • Fax: 213-576-1100

90 Park Avenue • New York, NY 10016 • 212-210-9400 • Fax: 212-210-9444

3201 Beechleaf Court, Suite 600 • Raleigh, NC 27604-1062 • 919-862-2200 • Fax: 919-862-2260

Two Palo Alto Square • 3000 El Camino Real, Suite 400 • Palo Alto, CA 94306-2112 • 650-838-2000 • Fax: 650-838-2001

2801 Townsgate Road • Suite 215 • Westlake Village, CA 91361-3020 • 805-497-9474 • Fax: 805-497-8804

The Atlantic Building • 950 F Street, NW • Washington, DC 20004-1404 • 202-756-3300 • Fax: 202-756-3333

April 1, 2010

Page 2

relied on the representations that the information presented in the Officer’s Certificate and the Prospectus accurately and completely describe all material facts relevant to our opinion. We have assumed that such statements, representations and covenants are true without regard to any qualification as to knowledge or belief. We are not, however, aware of any facts inconsistent with the representations contained in the Officer’s Certificate or the facts in the above referenced documents. Our opinion is conditioned on the continuing accuracy and completeness of such statements, representations and covenants. Any material change or inaccuracy in the facts referred to, set forth, or assumed herein or in the Officer’s Certificate may affect our conclusions set forth herein.

In rendering the opinion set forth herein, we have assumed the authenticity of all documents submitted to us as originals, the genuineness of all signatures thereon, the legal capacity of natural persons executing such documents and the conformity to authentic original documents of all documents submitted to us as copies.

Based upon the foregoing, and subject, in all respects, to the assumptions, qualifications and limitations set forth in this opinion letter, it is our opinion that:

The Company’s qualification as a REIT depends on the Company’s ongoing satisfaction of the various requirements under the Code and described in the Base Prospectus under the caption “Federal Income Tax Considerations” relating to, among other things, the nature of the Company’s gross income, the composition of the Company’s assets, the level of distributions to the Company’s shareholders, and the diversity of the Company’s ownership. Alston & Bird LLP will not review the Company’s compliance with these requirements on a continuing basis. No assurances can be given that the Company will satisfy these requirements.

An opinion of counsel merely represents counsel’s best judgment with respect to the probable outcome on the merits and is not binding on the Internal Revenue Service or the courts. There can be no assurance that positions contrary to our opinion will not be taken by the Internal Revenue Service or that a court considering the issues would not hold contrary to such opinion.

April 1, 2010

Page 3

The opinions expressed herein are given as of the date hereof and are based upon the Code, the Treasury regulations promulgated thereunder, current administrative positions of the Internal Revenue Service, and existing judicial decisions, any of which could be changed at any time, possibly on a retroactive basis. Any such changes could adversely affect the opinions rendered herein. In addition, as noted above, our opinions are based solely on the documents that we have examined and the representations that have been made to us, and cannot be relied upon if any of the facts contained in such documents or in such additional information is, or later becomes, inaccurate or if any of the representations made to us is, or later becomes, inaccurate. Finally, our opinion is limited to the US federal income tax matters specifically covered herein, and we have not opined on any other tax consequences to the Company or any other person, and we express no opinion with respect to other federal laws, the laws of any other jurisdiction, the laws of any state or as to any matters of municipal law or the laws of any other local agencies within any state.

This opinion letter is provided to you for your use solely in connection with the offering of the Notes and may not be used, circulated, quoted or otherwise referred to or relied upon by any other person or for any other purpose without our express written consent or used in any other transaction or context. No opinion other than that expressly contained herein may be inferred or implied. This opinion letter is rendered as of the date hereof and we make no undertaking, and expressly disclaim any duty, to supplement or update this opinion letter, if, after the date hereof, facts or circumstances come to our attention or changes in the law occur which could affect such opinion.

We hereby consent to the filing of this opinion letter as Exhibit 8.1 to the Registration Statement. In giving this consent, we do not hereby admit that we are an “expert” within the meaning of the Securities Act of 1933.