Posterior interosseous nerve injury is a serious problem which causes impairment of extension of fingers and radial deviation of wrist while extension. From anatomical point of view this nerve has a rather short segment from its main trunk to the muscular destination especially it branches rather early after it travels down from the main trunk. So in the past the repair of posterior interosseous nerve had been given up and many authors suggested to do the tendon transfer from the beginnings. However from our experience of several explorations, repair of this nerve seems to be possible and even can employ a nerve graft if any big gap is present. The uneventful result has been obtained in our cases so the tendon transfer should reserve until failure of the nerve repair. We presented four of our experiences to discuss the matter in detail.