The patient was a 18-year-old adolescent with a nonseminomatous germ cell tumor of the right testicle, with the presence of pulmonary, liver, and massive retroperitoneal metastases. Following radical orchiectomy, the patient started chemotherapy according to the BEP protocol (without routine prophylaxis for DVT). On day 4 of the first cycle, massive DVT was diagnosed, extending from both popliteal veins up to the thoracic segment of the inferior vena cava. Thrombolytic therapy with streptokinase was immediately started. On day 2 of thrombolytic therapy, the patient developed acute renal failure, due to extension of the thrombosis to the renal veins. Streptokinase was continued for six days and the outcome was remarkably favorable.