The axon regeneration following a peripheral nerve injury often fails to restore a complete functional recovery. One of the causes of this unsatisfactory result has been attributed to regrowth of regenerating fibers to inappropriate peripheral targets. The accuracy of reinnervation by axons regenerating across a 10-mm gap within an impermeable chamber has been studied by using a sequential retrograde double-labeling technique. Despite the long gap between the nerve stumps, at 4 weeks a mean of 30.5% of the regenerating axons can reinnervate the original muscular area. These data confirm previous studies in which a preferential reinnervation is reported not to be absolutely dependent on the axon's mechanical alignment.