We evaluated the modality of relapse and progression of medulloblastoma in 45 patients observed between 1981-1991. Children aged over 2 years were treated with surgery and postoperative radio-chemotherapy; among 12 children younger than 2 years, 8 were treated with surgery and chemotherapy and 4 with postoperative irradiation of remaining tumor. Cerebrospinal fluid shunting system was placed in 32 patients (71.1%). Patients were organized into three groups: group I (25 cases) = total tumor removal; group II (11 cases) = subtotal tumor removal; group III (9 cases) = partial tumor removal. 22 children died (48.8%: 10 of group I; 7 of group II; 5 of group III) at variable time interval from the operation during the following period. Among 23 alive patients, 3 are surviving with recurrence and progression of disease (all of group I), 20 are disease-free (44.4%: 12 of group I; 4 of group II; 4 of group III). Average postoperative follow-up period: 6 years for group I/II and 2 years for group III. Even if disease-free children are those treated by total-subtotal surgical removal (while local relapse occurs principally in patients treated by partial surgical resection: 44.4% of local relapse vs 12% of group I and 27% of group II), extensive surgery does not exclude possibility of metastatic localization in cerebrospinal axis, that occurs in 1/5-1/6 of all the patients without differences in each group. CSF shunting system did not cause extraneural metastases in our patients. We obtained long term survival rates or apparent recovery in almost 50% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)