Thirty-two patients with iliac and femoropopliteal artery occlusions were treated with direct intrathrombotic injection of ultrahigh-dose urokinase (10,000 IU/min). Occlusions ranged from 3 to 25 cm (average 13.3 cm) in length and the total urokinase dose from 120,000 to 1,410,000 IU (average 688,000 IU). The procedure was usually followed by balloon angioplasty to dilate the underlying stenoses. The initial recanalization rate was 96.9%, the two week patency rate 81.3%, and the cumulative one-year patency rate 66.3%. Complications associated with this procedure included three episodes of minimal bleeding, two distal embolisms, one local hematoma, and one low-grade fever. All were well controlled by palliative treatment. Results indicate that this procedure can provide rapid recanalization at a higher success rate and with fewer complications than previously reported.