The authors report a series of 30 adults with medulloblastoma treated after surgery between 1975 and 1990. Half the patients presented a classical medulloblastoma and the other half presented desmoplastic medulloblastoma. Brainstem infiltration was noted in 3 patients, cerebellar peduncle infiltration in 6 cases and 4 patients had cerebrospinal fluid (CSF) involvement. Tumor resection was achieved in all patients except 1, and in 5 surgery was incomplete. All patients but 2 received postoperative cerebral radiotherapy. Six patients did not receive chemotherapy before radiotherapy, 7 patients received CCNU-Vincristine concomitantly with and after irradiation, 1 patient was given a CHOP regimen, and the remaining 16 patients received the 8 drugs in a 1-day (8/1) regimen before irradiation. The median follow-up time was 104 months. The 5- and 10-year overall survival rates were 58.5% and 41%, respectively. Two toxic deaths occurred under the 8/1 regimen, and no better survival was observed for this group of patients in comparison with those receiving other regimens. Persistence of malignant cells in the CSF, brainstem involvement, cerebellar peduncle infiltration, non-radical surgery and a postoperative performance status (PS) of more than 2 were significantly correlated with an adverse outcome for overall survival in adult patients with medulloblastoma.