Clinical evaluations, nerve conduction studies, and electromyography play major complementary roles in electrophysiologic diagnoses. Electromyography can be used to assess pathologic changes and localize lesions occurring in locations ranging from motor units to anterior-horn cells. Successfully performing electromyography requires knowledge of the anatomy, physiology, and pathology of the peripheral nervous system as well as sufficient skill and interpretation ability. Electromyography techniques include acquiring data from visual/auditory signals and performing needle positioning, semiquantitation, and interpretation. Here we introduce the basic concepts of electromyography to guide clinicians in performing electromyography appropriately.