This article discusses three selected areas of sports medicine in which MRI is useful. The first is muscle injuries and includes the MRI findings in muscle tears, contusions, and myositis ossificans. The second section discusses the usefulness of MRI in imaging the athlete with groin pain, which is a difficult clinical problem for the orthopedist. The ability of MRI to differentiate between such causes of groin pain as osteitis pubis, bursitis, and stress fractures is shown. The final section covers plain radiographic and MRI findings in osteochondritis dissecans. Also discussed is the MRI staging of osteochondritis dissecans, which is important in treatment decisions and surgical planning.