Pioneer Southwest Energy Partners L.P.(“Pioneer Southwest”)(NYSE:PSE) today announced a cash distribution of $0.52 per unit for the quarter ended March 31, 2012, on Pioneer Southwest's outstanding common units, representing a $0.01 per unit increase in the quarterly distribution. This increased quarterly distribution equates to $2.08 per common unit on an annual basis. The distribution is payable May 11, 2012, to unitholders of record at the close of business on May 4, 2012. 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.