A total of 62 patients with retroperitoneal or genitourinary sarcoma was treated at our institutions during the last 46 years. Of the patients 51 were followed for at least 5 years or until they died (median followup 11 years); 5 patients were lost to followup. The most common site was the retroperitoneum. Liposarcoma, leiomyosarcoma and malignant fibrous histiocytoma were the most common tumors (74 per cent). Tumors were completely resected in 42 patients (68 per cent) and incompletely resected in 11, while a biopsy only was performed in 9. Some patients also received adjuvant radiation therapy and/or chemotherapy. There were no long-term survivors among patients with unresectable tumors. Over-all 3 and 5-year survival rates were 68 and 39 per cent, respectively. The histological type of the tumor appeared to have prognostic significance. The highest 5-year survivals were for liposarcoma (70 per cent), malignant fibrous histiocytoma (33 per cent) and leiomyosarcoma (13 per cent). The mean survival for patients after adjuvant radiation therapy or chemotherapy was similar to that after a radical operation alone. The primary cause of treatment failure was local recurrence (45 per cent of the patients), which was detected within 3 years of complete resection in most cases (82 per cent). Complete extirpation that provided adequate margins free of tumor was the most effective initial treatment and provided the best chance for cure.