Isolated dislocation of the tarsal navicular is very rare and its mechanism of injury and treatment is not well established. In our case, the naricular is dislocated plantomedially resulting from hyperplantar flexion, abduction injury with longitudial axial load. Open reduction and internal fixation was required because of pulling by tibialis posterior tender There was no traumatic arthritis at talo-navicular joint and naviculo-cuneiform joint and no evidenc of avascular necrosis of the tarsal navicular at postoperative 15 months follow-up.