High and low ulnar nerve injuries may result in decreased ulnar intrinsic muscle strength. Lateral or key pinch strength is significantly impacted due to the distance of the ulnar nerve lesion to the adductor pollicis and first dorsal interossei muscles, which are required for functional key pinch. Direct repair and/or decompression rarely result in adequate recovery of functional pinch strength. Success in regaining key pinch has been demonstrated with nerve transfers from the opponens pollicis brevis branch of the median nerve to the first dorsal interossei branch of the ulnar nerve. Postoperative rehabilitation following this nerve transfer begins within the first month following a 2-week immobilization period. Donor activation is encouraged with instruction in hourly palmar abduction of the thumb. Donor and recipient muscle patterning is performed with passive index finger abduction in the first phase of therapy and advances to active-assisted and active motion in the second phase. Gentle pinch activities are incorporated into the rehabilitation program by the end of the second phase, and pinch strengthening is introduced in phase 3 of rehabilitation.