A review of the English literature was undertaken to (1) determine the efficacy of radiation therapy for the treatment of brain metastases, (2) identify prognostic factors, and (3) ascertain whether there is an effect of treatment technique on outcome. Critical analysis of relevant randomized trials indicated that radiation therapy can effectively palliate the symptoms of brain metastases. Prognostic factors for improved survival are good performance status and the absence of a non-central nervous system tumor. The most efficient treatment protocol is controversial, but the literature supports the use of 20 Gy in five fractions for the treatment of patients with a poor prognosis. Patients with a solitary brain metastasis and no systemic disease benefit from resection of the brain metastasis followed by postoperative radiation.