From July, 1977, through December, 1978, a series of 33 patients with solitary brain metastases underwent surgical resection and postoperative radiation therapy at Memorial Sloan-Kettering Cancer Center. Sequential computerized tomography (CT) scanning was performed to determine the incidence of local recurrence and new brain metastases. The cause of death was identified by clinical follow-up study. The median survival for the entire group was 8 months, with a 1-year survival of 44%. Of the patients with no evidence of systemic cancer at the time of craniotomy, 81% lived 1 year. Local recurrence was noted in one patient known to have subtotal removal of tumor, and three patients developed carcinomatous meningitis. Of the 20 patients who died, four died within 30 days folowing surgery; three died of causes related to the central nervous system ((CNS); and 13 (65%) succumbed to systemic cancer. These data show that recurrence in the CNS following surgery and radiation therapy for single brain metastasis is low, and that serial CT scanning provides a much better measure of the effectiveness of treatment of this complication of cancer than survival times. It is suggested that results of CT and neurological examination be used as indices when comparing different modes of therapy for brain metastases. Significant furhter improvement in survival of these patients is dependent on control of systemic cancer.