Maintaining bone health in men who have advanced prostate cancer is an important goal of therapy. Low bone mass is prevalent in men who have prostate cancer, and long-term androgen deprivation therapy causes additional significant decreases in bone mineral density. The adverse effects of the disease and current treatment modalities on bone health are further compounded when patients develop bone metastases,which cause clinically significant skeletal morbidity. Treatment with bone-directed therapies, including intravenous bisphosphonates, radio-nuclides, and endothelin-1 antagonists, can provide palliative and therapeutic benefits for patients who have established bone metastases, and treatment with intravenous bisphosphonates may prevent the development of bone metastases.