Thirty-two patients with recurrent glioma who had previously received radiation therapy and chemotherapy with nitrosoureas were treated with intravenous carboplatin every 3 weeks, starting at a dose of 350 mg/m2, with a dose escalation of 25 mg/m2 every 6 weeks until a level 4 hematologic toxicity was reached. Of the 28 patients who could be evaluated for a response, 50% demonstrated a response or had stabilization of their disease after two infusions of carboplatin. Their median time to tumor progression and median duration of survival were 19 weeks and 38 weeks. Thrombocytopenia was the major toxicity and was severe in one-third of the patients. No neurologic or renal toxicities were noted. Carboplatin has demonstrated activity against recurrent gliomas in patients who have already had extensive chemotherapy. Increasing the dose of carboplatin may improve the rate of response and the duration of progression-free survival in patients with recurrent glioma.