In a group of 139 patients with poorly differentiated brain gliomas controlled clinical trial was carried out for assessment of two methods of postoperative treatment. After possibly radical removal of the glioma the patients were treated by radiotherapy with 60Co teletherapy in doses of 60 Gy (30 fr) in depth during 6 weeks, and randomly chosen patients received also CCNU in one dose of 100 mg/m repeated at intervals of 6-8 weeks. The administration of CCNU failed to improve the therapeutic results. The median survival time in the whole group was 49 weeks. The survival rate after 1, 2 and 3 years was 45.4%, 22.8% and 14.9% respectively. The survival times of cases of glioblastoma multiforme were not significantly different from those of patients with other poorly differentiated gliomas independently of the treatment method. The complications were not troublesome.