A prospective, randomized trial evaluates the effects of two postoperative treatment regimens on survival in 198 adult patients with supratentorial gliomas. All patients were irradiated with 6,000 rads after possibly radical removal of tumors. CCNU administration in the doses of 100 mg/sq m of body surface every 6-8 weeks following surgery proved to have no significant effect on the survival of patients. The median survival time in patients receiving radiation therapy alone was 61 +/- 7 weeks, while in those receiving additional chemotherapy was 56 +/- 4 weeks. Tumor histological malignancy and patients age were found to be the only important prognostic factors, irrespective of the treatment modality.