© 2015 Elsevier Ltd. All rights reserved. It has been estimated that primary or concomitant peripheral nerve injuries comprise 2-3% of Level I trauma center admissions in the USA annually, with the incidence rising to about 5% with the inclusion of brachial/lumbar plexus and other nerve root injuries. Peripheral nerve injuries may be sustained by a variety of mechanisms, the most common of which are stretch injuries and lacerations. Upper extremity nerve injuries occur more frequently than lower extremity injuries. The severity of peripheral nerve injury is classified based on the extent of disruption of the neural and connective tissue elements, most commonly via the Seddon or Sunderland classification systems. Aside from the invaluable history and physical exam, electrodiagnostic studies such as nerve conduction velocities and electromyography are important in the evaluation of peripheral nerve injuries and to help guide operative and non-operative treatment decisions. Following the initial assessment and determination of the type and extent of injury, either observation or surgical repair should be instituted. Operative lesions should be treated early, and lesions deemed non-operative which do not exhibit the expected progression warrant surgical exploration. The initial step in any type of repair is to clean the proximal and distal nerve stumps to expose healthy fascicles. Extra care must be taken to ensure the repair is not under tension and can withstand a physiologic range of motion. Surgical techniques for repair include end-to-end suturing of proximal and distal stumps, synthetic nerve grafts, interposition grafting with autologous donor nerves, and nerve transfer using a proximally intact adjacent nerve as a proxy for the proximal stump.