Metastases to the brain are a common complication of various cancers and are associated with poor prognosis. Management of these patients requires a multidisciplinary approach including whole-brain radiation therapy, stereotactic radiosurgery, surgical resection, chemotherapy, and supportive treatment. Because of recent technological advancements in genomics, our understanding of the genetics of brain metastases is rapidly advancing. This has led to the discovery of many potential genetic therapeutic targets in metastatic brain lesions. One of the limitations to systemic therapies is their limited ability to cross the blood brain barrier, necessitating the urgency to develop clinical trials to evaluate efficacy. A description of these genetic mutations, targeted therapies, and associated clinical trials in brain metastases from lung cancers, breast cancers, and melanoma is outlined in this review.