Cardiac arrhythmia frequently occurs under general anesthesia. It has been reported that cathecholamines increase the incidence of arrhythmia during anesthesia with halothane, which sensitizes the myocardium to the effects of cathecholamines. We experienced epinephrine-induced cardiac arrhythmia during anesthesia with halothane due to the inadvertent use of a large dose of epinephrine to achieve hemostasis. When the cardiac arrhythmia was noted by ECG, immediate tratment was performed and the result is summarized.