Angiomas are vascular malformations conceived as congenital anomalies. Surgical excision is the treatment of choice; an alternative is embolization. Radiation therapy is indicated: (1) for angiomas in vital or sensitive regions of the brain where they cannot be excised without the risk of a disabling neurological deficit and (2) for residual angiomas after partial embolization or incomplete surgical removal. The most effective radiotherapy for angiomas is radiosurgery. "Radiosurgery" is a term used for a special concept of radiotherapy. It describes stereotactically guided single high-dose irradiation. Therefore, a linear accelerator was modified at the German Cancer Research Center in Heidelberg. The precise localization of the target point and a steep dose gradient outside the target volume allow application of high doses to the tumor without damage to the surrounding normal brain tissue. Since 1984, in Heidelberg 41 patients with cerebral angiomas have been treated by stereotactic single high-dose irradiation (doses: 10-28 Gy). Eighteen patients were angiographically examined with a follow-up period longer than 18 months. In 7 patients, the pathological vessels was completely obliterated and in 6 partially. There was no change in 6 patients - all of whom received target doses of below 12 Gy.