Despite having been a recognized condition for more than many years, osteochondritis dissecans (OCD) remains a poorly understood disease of uncertain etiology. Osteochondritis dissecans is a focal idiopathic disease of the articular cartilage with instability and alteration which may result in early osteoarthritis of subchondral bone. Although the most common involvement is in the knee, OCD lesions can also be seen in other joints such as the elbow and ankle. In general terms, OCD lesions, regardless of location, can be classified as stable or unstable. Similarly, OCD patients can be classified into two dichotomous groups: skeletally mature and skeletally immature. Nonoperative treatments of activity restriction and immobilization should be reserved for skeletally immature patients who have stable lesions. Operative interventions should be considered if the lesion does not demonstrate progress toward healing after 6 months of treatment. Nonoperative treatment has demonstrated limited success in the treatment of unstable lesions in all age groups and in stable lesions in patients at or near skeletal maturity. In these groups, operative treatment should be considered as a first-line therapy. Operative options range from drilling, debridement and fixation techniques to advanced cartilage restoration, such as autologous chondrocyte implantation and osteochondral allografting.