The authors undertook a controlled, prospective, randomized study of 171 patients with supratentorial astrocytoma grades 3 and/or 4 (classified according to Kernohan). All patients were given chemotherapy consisting of procarbazine, vincristine, and lomustine (CCNU) (PVC). Half of the patients received whole-brain irradiation (RT) to a dose of 5800 cGy in the tumor-bearing hemisphere and 5000 cGy in the contralateral hemisphere. After diagnosis of progressive tumor growth, patients received individual treatment. The endpoint of the study was time to progression, but cases were followed until the patients died. Median time to progression (MTP) for the whole randomized population was 21 weeks. Median survival time (MST) was 53 weeks; 18% of patients survived for 2 years or longer. Survival analysis showed that patients less than 50 years of age treated with PVC plus RT had significantly longer MTP (81 weeks) and MST (124 weeks) than all other patients. For patients less than 50 years of age treated with PVC alone, MTP was 21 weeks and MST was 66 weeks. For patients more than 50 years of age treated with PVC plus RT, MTP was 23 weeks and MST was 51 weeks; in the PVC group, MTP was 17 weeks and MST was 39 weeks. Age, Karnofsky index, areas of Grade 2, and absence of extensive necrosis in the tumor were significant prognostic factors in the univariate analyses. Patients less than 50 years of age treated with PVC plus RT had significantly longer survival (P = 0.037) when correcting for these factors in a multi-variate analysis.