Radiopharmaceuticals not only are used for diagnostic purposes but also increasingly in the treatment of many orthopaedic-related disorders. With the development of specific bone-seeking radiopharmaceuticals, the side effects of treatment are minimized, therapeutic effects are sustained, and concomitant use with other modalities may have synergistic effects. These new radiopharmaceuticals, such as strontium 89 and samarium 153-ethylene diamine tetramethylene phosphate, have been used as palliative treatment for patients with bone pain from osseous metastases. Excellent clinical responses with acceptable hematologic toxicity have been observed, and clinical results rival those of external beam radiation therapy. Radiosynovectomy has become a procedure of choice at many institutions to treat recurrent hemarthrosis and chronic synovitis in patients whose hemophilia is poorly controlled with medical management. Radiosynovectomy also remains a viable option to treat chronic synovitis secondary to inflammatory arthropathies, particularly rheumatoid arthritis.