One hundred and six cases of brain tumors were treated at the Yonsei Cancer Center from Jan. 1972 to Aug. 1978by Co-60 teletheraphy unit. We analyses their clinical findings, histopathological findings, treatment andresults. In those cases which computerized tomography had been used before and after radiation theraphy, changesin tumor size and the presence of edema or necrosis following treatment was evaluated. 1. Among 106 cases, 90cases were primary brain tumors and 16 cases were metastatic brain tumors. Pititary tumors(38), glioma(34) andpinealoma(10) composed of most of primary brain tumors. 2. Post treatment follow-up was possible in 38 cases morethan 1 years. Four among 11 cases of glioma expired and survivors had considerable neurological symptoms except 2cases. Sixty five percent (12/20) of pituitary tumors showed improvement of visual symptoms and all cases (7) ofpinealoma which post treatment follow-up was possible, showed remarkable good response. 3. Finding of CT scanafter radiation treatment were compatible with results of clinical findings and post treatment follow-up. Itshowed complete regression of tumor mass in one case of pinealoma and medullobulastoma. One case of pituitarytumor showed almost complete regression of tumor mass. It also showed large residual lesion in cases ofglioblastoma multiforme and cystic astrocytoma.