Filed pursuant to Rule 433
Issuer Free Writing Prospectus dated June 15, 2009
Relating to Preliminary Prospectus Supplement dated June 15, 2009
Registration Statement No. 333-149583

Duncan Energy Partners L.P.

Pricing Term Sheet and Related Matters

8,000,000 Common Units

Issuer:		Duncan Energy Partners L.P.
Symbol:		DEP
Size:		$ 128,000,000
Units sold:		8,000,000 common units representing limited partner interests
Price to public:		$ 16.00 per common unit
Units outstanding after this offering:		57,676,987 common units representing limited partner interests
Net proceeds to DEP: (1)		$ 122,750,000
Option to purchase additional units:		1,200,000 common units
Trade date:		June 16, 2009
Closing date:		June 19, 2009
CUSIP:		265026104
Underwriters:		UBS Securities LLC
		Barclays Capital Inc.
		Citigroup Global Markets Inc.
		Morgan Stanley & Co. Incorporated
		Wachovia Capital Markets, LLC
		Goldman, Sachs & Co.
		J.P. Morgan Securities Inc.
		Raymond James & Associates, Inc.
		RBC Capital Markets Corporation
		SMH Capital Inc.
		Deutsche Bank Securities Inc.

Prior to purchasing the common units being offered pursuant to the preliminary prospectus supplement, on June 15, 2009, UBS Securities LLC purchased, on behalf of the syndicate, 390,000 common units at an average price of $16.4801 per unit in stabilizing transactions.

Duncan Energy Partners L.P. previously filed a registration statement (including a prospectus) on Form S-3 with the Securities and Exchange Commission (the “SEC”) for the offering to which this communication relates, which registration statement became effective on March 19, 2008. Before you invest, you should read the prospectus supplement to the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about Duncan Energy Partners L.P. and this offering. You may get these documents for free by visiting EDGAR on the SEC web site at www.sec.gov.

A copy of the preliminary prospectus supplement and prospectus relating to the offering may also be obtained from the following addresses: UBS Investment Bank, Prospectus Dept., 299 Park Ave., New York, NY, 10171, or by calling toll-free (888) 827-7275; Barclays Capital, c/o Broadridge, Integrated Distribution Services, 1155 Long Island Ave., Edgewood, NY, 11717, or by calling toll-free (888) 603-5847 or by email at barclaysprospectus@broadridge.com; Citi, Brooklyn Army Terminal, Attention: Prospectus Delivery Dept., 140 58th Street, 8th floor, Brooklyn, NY, 11220, by email at batprospectusdept@citi.com or by calling toll-free (800) 831-9146; Morgan Stanley, Attention: Prospectus Dept., 180 Varick Street, 2nd floor, New York, NY, 10014, or by calling toll-free (866) 718-1649 or by email at prospectus@morganstanley.com; Wachovia Securities, Attention: Equity Syndicate Dept., 375 Park Ave., New York, NY, 10152, or by calling toll-free (800) 326-5897, or by email at equity.syndicate@wachovia.com.