We administered chemotherapy in standard and intensified formulations of procarbazine, lomustine (CCNU), and vincristine to nine symptomatic patients with low-grade oligodendroglioma. Eight patients were treated with chemotherapy at presentation and one was treated for a recurrence after radiotherapy had failed. All patients improved by clinical or MRI criteria, or both. No patient deteriorated while in therapy and the responses were sustained without radiotherapy for a median of 35 months (range, 22-45) in all surviving patients treated at presentation. Chemotherapy was well tolerated; all patients developed myelosuppression, but only those receiving the intensified regimen required dose reduction or premature discontinuation of treatment. As with recurrent and anaplastic oligodendroglioma, low-grade oligodendroglioma responds to chemotherapy.