Stereotactically guided single-dose irradiation of brain metastases with low radiosensitivity has been performed in a series of 30 patients. Clinical symptoms improved in 18 of 27 evaluated patients and remained stable in another 7. Tumour regression was achieved in 13 of 22 patients, and arrest of tumour growth in 7 other patients. The treatment was usually well tolerated. The incidence of side effects was low. Thus, radiosurgery seems to be a valuable alternative to microsurgical extirpation of solitary brain metastases with low radiosensitivity.