Osteochondritis dissecans(OCD) of the knee is identified with increasing frequency in the adolescent patient. Left untreated, OCD can cause significant impairment and restriction in physical activity and development of osteoarthritis at an early age. The diagnosis of lesions of OCD can be confirmed on plain radiographs. MRI has emerged as the gold standard to evaluate the stability of the lesion and the integrity of the overlying articular cartilage. Treatment of OCD lesions depend on the stability of the lesion. Stable lesions can be treated conservatively by physical activity modification and immobilization. Unstable lesions and stable lesions not responding to conservative measures should be treated surgically. Surgical options range from arthroscopic drilling, either transarticular or extra-articular drilling for stable lesions or salvage procedures such as autologous chondrocyte transplantation (ACT), mosaicplasty to restore joint and cartilage congruency. and H. H. Shaikh, J. Vícha, T. Proček, J. Pavlata, T. Kučera