The most important cause of mortality in cancer patients is distant metastases. The third most common distant metastasis after liver and lung is bone. New inventions in cancer treatment has improved the survival of patients with metastatic cancers. As a result, clinical courses of patients are prolonged, and followed by morbidity due to bone metastases. Skeletal-related events, such as pathological fractures and spinal paralysis, cause impairment in activities of daily life, and quality of life. To avoid serious skeleton related events, early diagnosis and a prophylactic treatment are required. In this article, systemic treatment options for bone metastases will be discussed.