The dislocation of metacarpophalangeal joint of the index is apparently rare injury and produeed by striking of the volar surface of the outstretched index against a resistent object. This injury presents certain characteristics which make it distinctly different from dislocation of the thumb or little finger. The proximal phalanx is displaced over the dorsum of the corresponding metacarpal, the hand is deformed, and the index is inclined toward the middle finger. In 1957 Kaplan reported his study about the pathological anatomy and proper treatment technique in the dislocation of the metacarpophalangeal joint of the index finger. In this type of dislocation, closed reduction, even if performed immediately after the injury, is unsuccessful, and open reduction is mandatory. The authors have experienced a case of dorsal dislocation of the metacarpophalangeal joint of the index finger developed 3 weeks prior to admission on 20 th, May, 1985.