We present four cases of cerebral cavernous angioma that developed after radiatherapy for brain tumor in three cases and for cavernous angioma in one case. The time interval between irradiation and the detection of the cavernous angioma varied from three to nine years and the doses from 24 to 60 Grays. Brain hemorrhage appeared in two cases. Explanation for the formation of cavernous malformations is unclear but is probably related to proliferation and dilatation of the vascular endothelium with formation of capillary telangiectasis with evolution to cavernous angiomas. The pediatric brain appears particularly vulnerable to radiation injury. The risk of hemorrhage appears higher than with spontaneous cavernous malformations.