Treatment modalities for brain metastasis or metastatic brain tumor include surgery, conventional irradiation, stereotactic radiosurgery (SRS), chemotherapy, and supportive care with corticosteroid. In most cases, these treatments are used in combination. For a single metastasis, surgery followed by whole-brain radiation therapy (WBRT) has been the standard treatment. SRS has become increasingly popular and challenges the standard procedure, but there are still insufficient data for the outcomes of combinations including SRS. For the treatment of multiple metastases, WBRT is the standard procedure. For tumors larger than 3 cm, and in life-threatening situations such as a large metastasis to the cerebellum, surgery is the only feasible approach. Histological examination is sometimes useful for characterizing metastatic tumors from unknown primary sites. Thus, although brain metastasis invariably indicates a stage 4 cancer, some patients can benefit from surgery.