The authors review the cases of 144 children with medulloblastoma treated between 1950 and 1980. Duration of time between onset of symptoms and initial treatment was less than 1 1/2 months in 51% of cases, and less than 3 months in 76%. The tumor was located in the cerebellar vermis in 93% of patients. Brainstem infiltration was noted in 32%. Classical medulloblastomas comprised 82% of the total number reviewed, and desmoplastic medulloblastomas 15%. The majority of desmoplastic medulloblastomas were found in the midline of the cerebellum and in patients under 10 years of age. The prognosis for patients with desmoplastic medulloblastomas was worse than that for children with classical medulloblastomas. Spontaneous hemorrhage associated with primary or recurrent medulloblastoma occurred in 5.6% of the patients. Supratentorial metastases were found in 14.6% of cases, spinal cord metastases in 12.5%, and systemic metastases in 9%. The overall 5-year survival rate was 47%, and the 10-year survival rate 42%. Extent of surgical excision proved to be a statistically significant prognostic factor. Two patients developed recurrence after the 'period of risk' as defined by Collins' rule. Delayed complications of radiotherapy were found to be substantial. Intelligence quotient (IQ) testing on 16 survivors revealed verbal IQ, performance IQ, and full-scale IQ to be within the normal range in 11, seven, and nine cases, respectively. Two were retarded on all scores.