A 24 year old woman with a 15 year history of intractable seizures underwent resection of a small low grade astrocytoma of the right mesial frontal lobe. The tumor arose beneath a benign scalp nevus that had been treated in infancy with radium patches and focal x-irradiation. Neuropathological changes within the tumor were compatible with radiation injury. Meningiomas and sarcomas complicate cranial irradiation but the evidence that gliomas do so is less convincing. Our observations support an association between radiation exposure and the subsequent development of glial tumors.