The high volume of training involved in competitive swim training result in cumulative overload injuries. Knee pain ranks second to shoulder pain as a common complaint in competitive swimmers. Most knee pain occurs on the medial side of the knee and occurs most commonly in breaststroke swimmers; however, knee pain may occur in all strokes. This article will review the incidence, biomechanical and anatomic factors predisposing to injury, specific injury patterns, injury diagnosis, treatment, and prevention of injury to the knee in swimmers.