The role of routine use of duplex arteriography to diagnose thrombosis of popliteal artery aneurysm as a cause of acute lower extremity ischemia is investigated. In all, 109 patients (group 1) from 1994 to 1997 and 201 patients from 1998 to 2001(group 2) presenting with acute limb-threatening ischemia were studied. None of the group 1 patients underwent preoperative duplex arteriography, and no diagnosis of acute popliteal artery aneurysm thrombosis was made. Ten patients with acute ischemia due to thrombosed popliteal artery aneurysm were identified in group 2 when preoperative duplex arteriography was routinely performed. Urgent revascularization was performed based on the results of duplex arteriography. Six patients had functioning bypasses with a mean follow-up of 15.6 months. There were 3 deaths, 2 within 30 days and 1 after 21/2 years with functioning grafts. One patient was lost to follow-up. Routine use of duplex arteriography may provide the diagnosis and may identify the available outflow vessels for popliteal artery aneurysm.