Object Medulloblastoma is the most common malignant neuroepithelial tumor found in children. Several reports have described efforts to identify the prognostic significance of various patterns of pathological and immunohistochemical features in medulloblastoma, but the published data appear to be controversial. The authors therefore attempted to demonstrate these prognostic factors convincingly in a retrospective study performed in patients with medulloblastoma. Methods The data used were obtained in 58 patients with medulloblastoma who were > 3 years of age and in whom > 1 year of follow-up was available after the maximal resection, craniospinal irradiation, and chemotherapy treatments. These assessments were performed to compare the immunohistochemical features to cellular differentiation, the proliferation index (PI), the apoptotic index (AI), and oncogenesis revealed by TrkC and c-erbB-3. In addition, the authors tried to determine the prognostic utility of these results in this tumor category. Results There was no statistically significant correlation between the prognosis and the degree of cell differentiation, but a positive correlation was noted between the PI and the AI in a tumor mass. The number of cases with a PI > 10% was significantly greater in the group of tumors in patients with recurrent medulloblastoma. A close association between the PI as a continuous variable and the progression-free and overall survival was also found. Most importantly, the PI is the only significant prognostic factor for the overall survival of patients with medulloblastoma. Conclusions Therefore, the authors suggest that the PI is directly linked to the prognostic factor for medulloblastoma and that immunohistochemical staining is a potentially powerful tool for predicting the prognosis of patients with medulloblastoma.