A case of giant testicular tumor associated with scrotal gangrene is reported. A 33-year-old man had a swollen scrotum (15 cm) accompanied with necrosis and a foulodor. The tumor had invaded the scrotum, perineum and the left spermatic cord. Serum alpha-fetoprotein level was 15,487 ng/ml. The chest radiograph revealed multiple metastases. Bilateral high orchiectomies and local resection with a wide margin were performed. The tumor weighed 2.5 kg and the histopathological diagnosis was teratocarcinoma. He was treated with 3 courses of chemotherapy with cisplatin, etoposide and peplomycin. A second-look surgery revealed no viable cancer cells in the residual masses. The patient has been free of recurrence 4 months postoperatively.