At the Hungarian National Institute of Neurosurgery 73 recurrent supratentorial malignant tumours were treated by chemotherapy during the last ten years. Chemotherapy was applied after postoperative radiotherapy but in some cases following reoperation only. All cases were clinically and by CT or MRI verified recurrences. Forty-three patients received BCNU-DBD (dibromodulcitol) treatment (23 anaplastic astrocytoma--AA, and 20 glioblastoma multiforme--GM): day 1. BCNU 150 mg/sq.m. in i.v. infusion, day 2. dibromdulcitol 1000 mg/sq orally was given. This course was repeated every six weeks, altogether 2-8 times. Sixteen patients with AA responded with complete or partial regression but only 6 did with GM. Median survival was 14 and 7 months, the difference proved to be significant, p = 0.0091. PCV combination (procarbazine, CCNU, vincristine) was applied to 16 patients with AA and 14 cases with recurrent oligodendroglioma (O). Treatment started with vincristine 1.5 mg/sq.m. i.v. (2.0 mg maximum), the next day CCNU 100 mg/sq.m. was given, followed by procarbazine 60 mg/sq.m. on days 8-22. and finished by the same dose of vincristine on day 30. The course was repeated after one month, mostly six times. Six patients with AA did not respond; in cases of oligodendroglioma all but one responded with complete or partial improvement. It is remarkable that no significant difference was found between the survivals of BCNU-DBD or PCV treated AA patients. Chemotherapy of supratentorial malignant glioma recurrences with nitroso-ureas and their combination proved to be efficacious. It also seems, that in recurrent cases lower grade gliomas show better response rate than glioblastomas.