Radionuclide scans with improved imaging techniques such as single-photon-emission tomography and three-phase scanning have become safe, well-established, and highly effective diagnostic tools in sports medicine. The greatest strengths of the techniques include providing early physiologic information about injury sites and evaluating large areas or the whole body in a single examination. As described and illustrated here, bone scans are particularly useful for diagnosing such musculoskeletal injuries as stress fractures, avulsion fractures, periostitis, myositis ossificans, and rhabdomyolysis.