Aortoiliac aneurysmal dilatation may extend to involve the internal iliac artery in certain cases of generalized atherosclerosis. The presence of a symptomatic, isolated aneurysm of the internal iliac artery (hypogastric artery) represents an unusual finding. Such a lesion may manifest itself clinically by sudden rupture, pain, or localized pelvic symptoms involving the adjacent segments of the gastrointestinal or genitourinary systems. The 3 cases presented illustrate these findings, and the proper surgical management is suggested. A similar case presenting with urinary tract obstruction secondary to an aneurysm of the hypogastric artery was reported in 1947 by Goodwin and Shumacker.1 Report of Cases Case 1. —The patient was a 76-year-old white man who was first seen in the emergency division of the Strong Memorial Hospital, Rochester, on March 9, 1960. There was a 6-month history of lower abdominal pain which had increased in severity over the past 3 weeks, and which