We have treated 14 patients with acute arterial thrombosis with intravenous infusion of streptokinase using a standard dosage scheme. The indication for treatment was critical ischemia due to arterial thrombosis and a presence of symptoms for less than 30 days. The arteriography showed no possibility of reconstructive vascular surgery. The results showed that this treatment is not a good alternative for this group of patients. On the same indications we also treated two patients with intra-arterial infusion of streptokinase at a dosage of 5,000 U per hour. Successful thrombolysis was achieved in both patients. Arteriograms demonstrated that the small distal vessels were opened, along with the femoro-popliteal segment, which showed significant stenosis. The patients could then be helped by reconstructive vascular surgery. We conclude that thrombolysis with intra-arterial infusion of streptokinase is a good choice as the initial treatment for this group of patients. However, the follow-up must include immediate reconstructive vascular surgery or radiological treatment with PTA.