The transcatheter injection of fibrinolytic agents is now the treatment of choice of the acute occlusions of the peripheral arteries. We retrospectively compared the efficacy and safety of two fibrinolytic agents (urokinase and recombinant tissue-type plasminogen activator) in 83 consecutive patients: 37 with occlusion of surgical bypass grafts, 36 with occlusion of atheromatous vessels, 5 with post-angioplasty occlusion, 2 with post-traumatic thrombosis, 2 with cardiogenic emboli and 1 with thrombophilia. Recanalization was achieved in 55 of 59 (93%) patients treated with urokinase and in 21 of 24 (88%) patients treated with recombinant tissue-type plasminogen activator (p > 0.05). The latter provided a more rapid recanalization than urokinase but was also responsible for the complications observed in all 10 (12%) patients. These results indicate that urokinase is to be preferred to recombinant tissue type plasminogen activator for routine arterial transcatheter fibrinolysis.