In November 1985, we started a study of intra-arterial (i-a) chemotherapy with ACNU for the treatment of glioblastomas of the central nervous system: 19 patients with histologically proved glioblastoma and recurrent, progressive or newly diagnosed disease were entered. Five patients were treated three times. We observed reduction of mass effect, of neovascularization, and of contrast enhancement. As to the time of survival, or follow-up is too short to allow definite conclusions. The quality of life in those patients who received several courses of chemotherapy, did not deteriorate as evidenced by a constant Karnofsky performance rating score. Systemic complications of i-a chemotherapy were negligible. However, some severe side-effects were seen: cerebral ischemia in two cases, and amaurosis in one. Direct ACNU related neurotoxicity was not seen to the present. According to these preliminary results, we feel encouraged to treat further patients with i-a chemotherapy, particularly in view of the disappointing results of several other treatment modalities in the management of glioblastomas of the brain.