Arthroscopy is an important technique in the diagnosis, classification, and treatment of the athlete with OA. Reliability of the current classification systems improves with training and experience. Arthroscopy remains superior to imaging in the diagnosis of OA. Arthroscopic lavage and debridement provide benefit in a significant percentage of patients. The reasons for improvement are not fully defined. Arthroscopic treatment of OA is not curative, and results deteriorate with time. Variability in the use of medical management, arthroscopy, osteotomy, and arthroplasty remains among different practitioners. Indications for arthroscopy require further clarification based upon empiric evidence.