Metastatic bone disease is common, and affects more than 5 million individuals in the United States. Patients may present with bone pain. If a patient is known to have a cancer that commonly spreads to bone (ie, kidney, lung, breast, prostate, thyroid), metastatic bone disease should be considered as a cause. Bone metastases also may be detected incidentally on x-rays. For patients not known to have a cancer, medical history, physical examination, and laboratory tests may indicate the primary malignancy site. X-ray is the primary imaging modality, but magnetic resonance imaging study, computed tomography scan, and nuclear medicine studies also may help identify the site of the primary tumor and extent of metastatic disease. The diagnosis is confirmed with surgical or percutaneous biopsy. Patients with bone metastases are at risk of pathologic fractures, and measures should be taken to prevent these, such as avoidance of weight-bearing on affected extremities or surgical fixation. Patients also should receive, as appropriate for the type of cancer, chemotherapy, radiation, and other treatments. Drugs to promote bone health (eg, bisphosphonates, denosumab) should be considered for all patients with metastatic disease. (This is an off-label use of some bisphosphonates.) When appropriate, palliative care is indicated.