Twenty patients with malignant supratentorial gliomas progressing after radiation therapy and chemotherapy with nitrosoureas received intravenous carboplatin, 450 mg/m2. Courses of therapy were repeated every four weeks. Therapeutic evaluation was performed monthly using neurologic examination and CT scan of the brain. Of 19 patients evaluable for response, 2 (10%) responded to therapy and 6 (30%) had stable disease. The estimated median time to tumor progression for responding and stable patients was 6 months. Median duration of survival was 6 months for all patients. Of 20 patients evaluable for toxicity, none had renal or auditory toxicity. Side effects consisted of hematologic toxicity in 4 patients (20%): one patient had grade 4 toxicity requiring discontinuation of carboplatin and 3 patients had grade 2-3 toxicity.