The Taser is an electrical law enforcement and self-defense weapon that is being used with increasing frequency. The weapon is described and its effects and ballistic and electrical considerations are reviewed. Clinical aspects of Taser injury, including weapon-fired barb injury, barb removal methods, injury secondary to electrical current, ventricular fibrillation, possible interactions with implanted pacemakers, and injuries secondary to weapon-induced falls, are discussed. Taser injuries are a new and increasingly frequent emergency medicine problem.