In this retrospective study, the result of 17 adult patients with oligodendroglioma were treated by radiotherapy postoperatively or as only treatment modality at Saint Luke's Hospital between 1968-1979 are presented. The following surgical treatments were applied. Three patients (% 18) had grossly complete excision, nine patients (%53) had incomplete tumor resection and five patients (% 29) had only biopsy. All of the patients received radiation-therapy within two weeks time. Radical dose radiotherapy were applied %59 of patients and others had palliative dose therapy. The crude 5 year survival rate was % 41 and median survival value for dead patients was 30 months. Prognostic factors such as age, extent of surgical resection, dose of radiotherapy and grade of tumors were not compared statistically in two groups since the number of patients are not enough in each group. However survival of patients in each prognostic groups were reported and treatment results were compared with literature.