Background: Central nervous system tumors account for 2%-5% of all malignancies in humans. These tumors account for 2% of all pediatric cancers. The worldwide incidence of primary central nervous system tumors is estimated at 3.9 (males) and 3.2 (females) per 100000 person-years. The incidence of brain tumor cases has been reported as 3.67% of all malignancies and 4% of all cancer mortalities in Iran. The five most common histological types of brain tumor in Iran according to different case studies are; meningioma, astrocytoma, glioblastoma, pituitary adenoma and ependymoma. The aim of this study is to determine the histopathological pattern and characteristics of patients with brain tumors who have referred to the Mahdieh Radiotherapy Department, Hamadan, Iran. Methods: This descriptive, retrospective study was performed at the Mahdieh Radiotherapy Department, between 2005 and 2012. We included 220 patients who referred to the Radiotherapy Department with diagnoses of primary brain tumor in this study.Results: Between 2005 and 2012, we treated 220 new cases of primary brain tumor at Mahdieh Radiotherapy Department. The mean age at diagnosis was 39.95±15.48 years with a median age of 39 years. Patients' ages ranged from 4 to 75 years. Among the 220 patients, 138 were male and 82 were female with a male to female ratio of 1.68. For most tumors there was a male predominance, with the exception of meningioma (M/F: 0.23), ependymoma (M/F: 1) and pituitary adenoma (M/F: 0.6). Astrocytomas, glioblastomas, high grade meningiomas and oligodendrogliomas were the four most common pathologies treated in this department. The best treatment results were achieved in patients with astrocytomas.Conclusion: The present study is a retrospective radiotherapy centre-based study designed in a pioneer radiotherapy centre in Western Iran, not a prospective population study. These data have provided a baseline for further epidemiological studies. Our encouraging results in radiotherapy treatment of primary malignant tumors clearly highlight the benefits of definitive or postoperative radiation.