Background and Design.- A retrospective study was designed to evaluate the results of pos¬toperative crainiospinal irradiation and prognostic factors in,adult medulloblastoma patients. Twenty-nine adult medulloblastoma patients (> 16 years of age) presented to our department for postoperati¬ve radiotherapy were analysed. Median age was 26 (16-44), median duration of symptoms was 3 months (1-12). Male/female ratio was 19/10. Se¬venteen of the tumors (58.6%) were located late¬rally and 9 (31%) were of desmoplastic variant. Gross total resection was performed in 18 patients (62.1%) and 10 (34.5%) received adjuvant che¬motherapy. As a standard treatment 19 patients were given craniospinal irradiation and posterior fossa was boosted. Median dose to the whole bra¬in was 45 Gy (36-60 Gy), spinal axis 36 Gy (24-40 Gy) and posterior fossa 54 Gy (49-60 Gy). Results.- Five year local control, disease free survival and actuarial survival rates for standard treatment group were 84%, 65.9% and 53.3% res¬pectively. Female gender was found to be a bad prognostic factor between the factors analysed. Conclusion.- Postoperative craniospinal irradi¬ation should be given to all patients with medul¬loblastoma to prolong survival.