Of primary concern in peripheral nerve injuries is evaluation according to mechanism of injury, evidence of clinical dysfunction, and quality of responce to diagnostic tests. Surgical intervention may be necessary in open or closed injuries and is elected in either case when the return of function has not been demonstrated or is not expected on the basis of the mechanism of injury. Surgical exploration may be part of diagnosis and is usually indicated in open wounds. A nerve which is divided surgically for the excision of a tumor or other lesion may well be sutured primarily. Delayed suture, however, is preferable in the case of injury either sharply incised or heavily contused. Stretch injuries rarely require operative treatment, but they, with all others, will demand thoughtful supportive therapy.