We performed retrospective review of 29 adult patients with cerebellar medulloblastoma/primitive neuroectodermal tumor (PNET) who received craniospinal radiotherapy in Ankara Oncology Hospital between years 2000 and 2005. All patients were operated followed by craniospinal irradiation; 11 of 29 patients also received chemotherapy. All patients had no distant or spinal metastases at the time of diagnosis. Median follow up time was 26 months. Progression-free survival was 86% at 2 years, 55% at 5 years. Mean progression-free survival was 25 months in patients with PNET; 61.4 months in patients with medulloblastoma (P = 0.0016). Mean survival was 61.33% months in patients < 25 age, 38 months in patients > 25 age. (P = 0.04). Overall mean survival was 59.80 months in patients who received chemotherapy and 41.4 months in patients who did not have chemotherapy (P = 0.15). Cranial relapses were observed in 3 of 29 patients, and 3 of 29 patients had distant metastases. The mean time to cranial recurrence was 19 months; to distant metastases was 18 months. In conclusion, adult patients with PNET have worse survival rates than patients with medulloblastoma, like in childhood patients. Patients younger than 25 years of age also had statistically significant better survival.