A retrospective review was performed of 72 cases of cleft palate operated at the Nati-onal Medical Center from March 1985 to June, 1986. We evaluated the frequency of cardiac arrythmia and changes in the heart rates when epinephrine is used with halothane anesthesia in pediatric patients for the closure of palate. 21 children (29.2%) developed several types of ventricular dysrrhythmias and one child had ventricular fibrillation. 41 children(65.37) had increase in heart rates, and 23 children had no change after epinephrine injection. All children restored sinus rhythm after 100% oxygen inhalation lidocaine(1-1.5 mg/kg) , and demerol (0.5-1 mg/kg) were injected.