Pioneer Southwest Energy Partners L.P. (?Pioneer Southwest?) (NYSE:PSE) today announced a cash distribution of $0.50 per unit on Pioneer Southwest's outstanding common units for the quarter ended December 31, 2010. The distribution is payable February 11, 2011, to unitholders of record at the close of business on February 3, 2011.

Pioneer Southwest is a Delaware limited partnership, headquartered in Dallas, Texas, with current production and drilling operations in the Spraberry field in West Texas. For more information, visit www.pioneersouthwest.com.

Pioneer Southwest Energy Partners L.P.
Investors:
Frank Hopkins, 972-969-4065
or
Brian Hansen, 972-969-4017
or
Media and Public Affairs:
Susan Spratlen, 972-969-4018
or
Suzanne Hicks, 972-969-4020