Osteochondral fracture is common in adolescent and usually occurs in the knee and ankle. Many authors have written concerning osteochondral fracture of the ankle joint, however, many of these pertain only to the talus. The author has found an osteochondral fracture of the articular surface of the medial malleolus within the ankle joint not previously described. We report a case of this lesion that was treated by arthroscopic osteochondral fragment removal.