The argon plasma coagulator is a device used for noncontact thermal coagulation of tissue. The device was first used in open and laparoscopic surgical procedures and in 1991 was adapted for use in endoscopy. Since then, argon plasma coagulation has expanded its clinical applications in the treatment of various gastrointestinal conditions. The endoscopy nurse plays an important role in the care of patients before, during, and after argon plasma coagulation treatment. This article reviews the principles and components of the argon plasma coagulator, and provides a summary of the various clinical applications, patient safety practices, and potential complications of argon plasma coagulation therapy.