We enhance the value of electrodiagnostic studies when we discuss prognosis after nerve injuries. Nerves are variable in their mechanism, location, and pathophysiology of injury. Several factors currently known to influence prognosis include the nature of the nerve trauma, amount of axon loss, recruitment in muscles supplied by the nerve, extent of demyelination, and distance to reinnervate functional muscles. Generally, findings of large motor responses, intact recruitment in muscles supplied distal to the injury, and the presence of a conduction block are associated with a better prognosis. This article discusses nerve-specific information as well.