Oligodendrogliomas are uncommon tumors that develop from oligodendrocytes. They may be pure or associated with astrocyte proliferation. these tumors affect middle-aged adults and are characterized by their slow growth and their fairly suggestive neuroradiological features which are those of a large. calcified poorly enhanced. peripheral frontal lesion. They are usually benign. but their clinical behavior is variable In a retrospective study of 56 cases with pure oligodendroglioma. the 5-and 10-year survival rates were 61% and 42%. respectively. The influences of the age and sex of the patient. size. location and other radiological findings. The extent of surgical resection. effect of additional radiation therapy and pathological findings of the tumor were investigated Among the 14 prognostic factors. the location and pathological findings of the tumor significantly affected the survival rates of the patients. But. the extent of extent of resection and additional radiation therapy were not related to survival.