From November 1982 to August 1990, 16 patients with primary retroperitoneal sarcoma were treated in our hospital. The most frequent types of tumor were liposarcoma (6), malignant fibrous histiocytoma (3). The commonest clinical findings were palpable abdominal mass (14/16). In management of these patients; nine patients underwent complete resection of the tumor; three patients underwent partial resection of the tumor and four patients underwent biopsy only. The histology of tumor appeared to have prognostic significance. Patients suffering from liposarcoma (3/5) and malignant fibrous histiocytoma (1/2) survived the longest. With a mean follow up of 25.0 months, the three year overall survival rate of complete resection group was 50 per cent. No patients with partial resection and biopsy only group survive three years and the total three-years overall survival rate was 29%. The mean survival for patients after adjuvant chemotherapy and/or radiotherapy was similar to that after a radical operation alone. The prognosis of primary retroperitoneal sarcoma is grave and complete resection of the tumor as initial treatment seems to provide the only chance of cure for these patients.