From January 1988 to October 1993, forty-five patients with histologically confirmed intracranial malignant gliomas were treated with post-operative radiation therapy in our department. They were subjected to this analysis according to the extent of surgery, postoperative Karnofsky performance status, age, histology grading, sex, radiation doses, and presence or absence of seizures. There were 26 males and 19 females between 11 and 67 years of age. The median survival for patients with anaplastic astrocytoma and glioblastoma multiforme was 11.9 and 11.5 months, respectively. The postoperative Karnofsky performance status, extent of surgery, and the multiplicity of lesions were identified as significant prognostic factors.