Acute patellar dislocation is a common injury in young athletes, which occurs due to inappropriate biomechanical relations and anatomic deviations in the area of knee joint. In these unfavorable conditions, abrupt and vigorous strain of the quadriceps muscle of the thigh may result in lateral patellar dislocation. A case is presented of a young male athlete with acute patellar dislocation and consequential osteochondral fracture. Although x-ray showed normal knee finding, typical history, clinical examination and magnetic resonance image of the knee indicated arthroscopy, which confirmed the diagnosis ofpatellar dislocation. The osteochondral fragment was found and fastened by screws, thus reconstructing the articular surface of the patella. Medial patellar stabilizers were strengthened and lateral stabilizers loosened, thus re-establishing its anatomic slide way. On second-look operation, the screws were removed. In this case, good anatomic and functional outcome was achieved by timely operative treatment, joint surface reconstruction and rehabilitation.