Twenty-four patients with recurrent malignant glioma were treated with intravenous BCNU (80 mg/m2/day X 3 days) alternating with AZQ (8 mg/m2/day X 5 days) every 6-8 weeks. Twenty patients received two or more courses of chemotherapy, ten anaplastic astrocytomas (AA), eight glioblastomas (GBM), and two malignant oligodendrogliomas (Oligo). All had prior surgery and irradiation; one had prior chemotherapy. Median age was 37.5 years. The median Zubrod performance status (PS) was 1. Three patients (15%) achieved response status, and 7 (35%) had stable disease with median times to tumor progression (MTP) of 56 wks and 35 wks. MTP for patients with progression was 11 weeks. No GBM was responsive to chemotherapy and none of the ten patients with stable or responsive disease were older than fifty years. Dose limiting toxicity was consisted of thrombocytopenia and leukopenia. Young patients with recurrent AA and good PS appear more likely to respond to alternating BCNU/AZQ chemotherapy. The overall response rate (response plus stable) of 50% was comparable to that of BCNU alone and the hematologic toxicity was cumulative.