Medulloblastoma is one of the most common malignant infratentorial tumors in children. At the present, it is difficult to treat these tumors in Vietnam. The treatment was better, if the patients were diagnosed earlier. The study was carried out to assess the results of treatment of medulloblastoma in children at the National Hospital of Pediatrics in three years (from August 2008 to July 2011). The results showed that there were 38 children patients with medulloblastoma in three years. The main signs are headache, volmiting, cerebellum symtoms and papiloedema. The treatment were included surgery, radiotherapy, chemotherapy. The postoperation, the 44.7 percent total patients were resected with total tumours, 34.2 percent with the part of tumours of resection, 5.3 percent with only biopsy, the 15.8 percent total couldn't performed MRI or CT after surgery. The number of patients with radiotherapy are 16, include 14 finishes and 2 patients with incomplete There were 14 patients with chemotherapy include: 9 finishes, 2 incomplete and 3 patients are treating now. There were 16 patients with radiotherapy, of which 14 cases finished radioation treatment, one case of withdrawal of treatment by his parents, another one due to the patient could't co-operate. There were 14 patients with treatment by chemotherapy, but 2 of them dropped out. The 19 patients died in the first three months, 4 patients died in the later stages, and 15 patients are still living with goodhealth. The average .survival time of patients who died was 110.5 days. In conclusions, mortality rate was so high, however the treatment will be better if the patiens were diagnosed ealier.