Three patients developed cerebral gliomas decades after exposure to low-dose x-ray irradiation in childhood for the treatment of tinea capitis. One of the patients had a glioblastoma multiforme concomitant with multiple intracranial meningiomas, a condition highly correlated with previous irradiation. The other tumors were malignant cerebellar astrocytoma and a diffuse cerebral astrocytoma. We review the evidence suggesting that low-dose irradiation is involved in the pathogenesis of gliomas.