Osteochondritis dissecans (OCD) of the knee has multiple possible etiologies. Among these are repetitive microtrauma, disruption of normal endochondral ossification, as well genetic factors. The male to female ratio is approximately 4:1 in the United States and has been found to have the highest incidence in the African American population. Diagnosis is usually made by physical examination in association with radiographs (flexion notch view) and magnetic resonance imaging. Lesions are usually found on the lateral aspect of the medial femoral condyle. Arthroscopy continues to be the gold standard for assessing the stability of OCD lesions. Many unstable lesions may be treated with stabilization, and cartilage restoration may provide benefit; however long term data is still limited.