Between January 1980 and May 1985, 102 patients (68 men, 34 women, median age 47 years) with malignant brain tumours (35% glioblastoma multiforme, 30% astrocytoma grade III, 21% oligodendroglioma grade III) have been treated in our clinic. All tumours were inoperable because of their size and/or location. The diagnosis was confirmed histopathologically (stereotactic biopsy or subtotal resection). Seventy-five patients without previous radiotherapy received three courses of a concomitant radio- and chemotherapy with free intervals of 5 weeks between the courses of the therapy. Using lateral opposing fields the whole brain was irradiated with 60Co in daily fractions of 1.5 Gy up to 15 Gy per course of the treatment. Simultaneously, all patients received ifosfamide on five consecutive days in a dosage of 1.2 g/sqm body surface each day i.v. On days 1, 3 and 5, BCNU was given additionally in a daily dosage of 30 mg/sqm body surface i.v. After three courses, a total radiation dose of 45 Gy was administered to the whole brain. Directly after the last cycle of the combined treatment the primary tumour was boosted up to 50-60 Gy using smaller portals. Seventy-one of the 75 patients were amenable to statistical analysis. The overall tolerance was good. No severe haematological or gastrointestinal complications occurred. According to the criteria of the UICC, 12 complete remissions (CR) (i.e. 16.9%) and 35 partial remissions (PR) (i.e. 49.3%) were achieved. In 21 cases (i.e. 29.6%), the progression of the tumour could be stopped. Depending on the histopathological classification of the malignancies survival rates between 64.3% and 87.5% were achieved for one year.(ABSTRACT TRUNCATED AT 250 WORDS)