At the Kyung Hee Medical Center all patients receiving general anesthesia in the operating room are monitored continuously with electrocardioscope, Burdick CS-515 Monitor, and recorded by EK4S ECG. Among 50 patients 18 cases (36%) developed a variety of arrhythmias. Seven (14%) were considered serious in nature, such as ventricular extrasystoles. There was an increased incidence of arrhythmias during induction of anesthesia, in old age group and in poor risk patients. Continuous cardiac monitoring is valuable, easy, and practical in virtually all instances during anesthesia and surgery.