Electrosurgery has proliferated since its original application by William T. Bovie and Harvey Cushing in the 1920s. Because surgeons use this technology frequently, a thorough understanding of these instruments and their potential complications is critical to their safe and successful use. Electrosurgical units operate on basic fundamental principles of physics and involve the passage of electrical current through tissue to create the desired tissue effect. With knowledge of the history, physics, techniques, histological effects, and safety issues of electrosurgery, the field will continue to proliferate and electrosurgery will continue to assist surgeons in alleviating human suffering.