Peripheral nerve injury has been the focus of surgical research for centuries. Initial advancements included not only identifying nerves in vivo and differentiating them from surrounding structures such as tendons, but also understanding their function and unique anatomy. The understanding of the physiology of neurotrophic factors and the relationship to axonal regeneration has contributed to developing new methods of nerve repair. Operative exploration of an injured nerve involves assessment of many factors that will decide if a primary or secondary repair will be performed. The vascularity of surrounding tissue, the amount and quality of soft tissue coverage, the type of nerve injury, the age and general medical condition of the patient, and associated injuries are some of the factors that are assessed. Types of primary repair include epineurial and perineurial. Different methods of facilitating differentiation of motor and sensory fascicles include electrostimulation and histochemical staining techniques. Once the nerve is identified and trimmed back to viable tissue, any type of nerve gap must be assessed. If there is tension at the reapproximation site or significant gap, a nerve graft can be done at a secondary surgery. Other options include using polyglycolic acid or vein graft conduits. New contributions continue to be made as our understanding of peripheral nerves advance on the biochemical, physiologic, and anatomic levels.