Brain tumors are the most common solid tumor malignancies in childhood, and among them, medulloblastoma occurs with the greatest frequency. Because medulloblastomas occur in the posterior fossa, the presenting symptoms often are vague complaints and diagnosis may be delayed. Between 70% and 80% of patients who are diagnosed before metastatic dissemination survive, compared with 30% to 40% of those in higher risk groups. This article reviews the diagnosis, treatment, and prognosis for medulloblastoma.