Osteoarthritis (OA) is currently a major health problem, both with an important individual and socio-economical impact. The diagnostic of osteoarthritis is both clinical and radiological, without a strong correlation between symptoms and radiographic findings. Participation in sports increases the risk of joint overuse or injuries potentially leading to posttraumatic osteoarthritis. Conversely, sport is a recognized therapeutic and probably also a preventive tool against osteoarthritis, with a positive influence on weight, muscle strength and possibly synovial inflammation. In general, sport should be encouraged individually with an appropriate program and a correct intensity.