Intraarterial thrombolytic therapy was performed in 36 patients with acute arterial occlusions of the extremities. Intraarterial thrombolytic therapy was effective in 19 of 24 patients (79.2%) with embolic occlusions. However, the results were poor in patients who had multiple arterial occlusions including those at sites other than the extremities. Only four of 12 patients (33.3%) with thrombotic occlusions had good initial technical results. Six patients died shortly after the thrombolytic procedure, and seven patients underwent amputation. The long-term patency rate of 21 patients who were treated successfully was 92.7% after one year and 74.6% after five years. Intraarterial catheter thrombolytic therapy was effective for embolic occlusion even when more than six hours had elapsed from the onset of symptoms. The indications for thrombotic occlusions may be limited, since associated marked atherosclerotic change was often present.