Over the last several decades in Europe and 15 years in North America, numerous centers have used stereotactic high-activity brachytherapy for patients with malignant brain tumors. A number of nonrandomized series have contributed information regarding the efficacy compared to historical controls for patients with de novo and recurrent malignant gliomas and metastases. Two randomized studies for patients with de novo malignant astrocytoma and glioblastoma are nearing completion. Based on the author's personal experience with 115 patients and the reported literature, we conclude that brachytherapy is appropriate for a minority of patients with malignant brain tumors, that reoperation is frequently required, and complications of therapy can be significant. However, a proportion of highly selected patients benefit significantly from this therapy.