Osteochondritis usually occurs in the epiphyseal center of children. Common sites of involvement of osteochondritis are the femoral head, tarsal navicular, talus, lunate, but the patellar involvement is rare. The exact cause of osteochondritis is unknown but it is believed to be traumatic or nontraumatic (idiopathic) in origin. This disease was first described by Kohler in 1908 and characterized by radiographic finding of increased density in the patella We have experienced here one case which is believed to be osteochondritis of the patella.