Ninety-three patients with primary intracranial brain tumors recurrent after cerebral irradiation were treated with aziridinylbenzoquinone (AZQ; Diaziquone). Twenty-four (26%) had tumor regression lasting a median of 9.2 months. Prior chemotherapy was not significantly associated with tumor regression but was associated with survival (median 7.3 months no prior chemotherapy versus 4.7 months with prior chemotherapy; logrank p = 0.03). AZQ demonstrated anti-tumor activity in a wide variety of primary intracranial neoplasms recurrent after radiation therapy and deserves study in patients at the time of diagnosis. We believe alternating or combining AZQ and BCNU should be rewarding. The principal toxicity of AZQ is myelosuppression.