Injuries of the median nerve cause two major syndromes. Interosseous nerve injury as it branches from the median just below the elbow produces a characteristic deformity. Treatment involves neurolysis, or primary or secondary repair. Various tendon transfers can be used to compensate for lost function. The other syndrome is produced by median nerve injury at the wrist and consists of thenar muscle paralysis and a sensory deficit on the radial aspect of the palm and radial 3 1/2 digits. The carpal tunnel syndrome is the most common cause. Treatment consists of incising the volar carpal ligament. Lacerations at this level should be repaired primarily if possible. Several types of opponensplasties are available to restore thumb opposition. Median nerve injuries impair the ability to pinch and should be carefully evaluated and treated.