Four cases of proximal deep venous thrombosis treated with streptokinase and tissue plasminogen activator are reported. Therapy monitorization was performed by ultrasonography with color Doppler and thrombolytic agents were used by venous infusion. There was complete lysis in two cases, and the mean rate of venous recanalization was 88%. Reversible hemorrhagic complications were observed in two patients, and late ultrasonographic control (after six months) demonstrated venous insufficiency in one case.