The pharmacological actions of ketamine in human volunteers were reported by Domino et al. in 1965, and use in 130 patients by Corssen and Domino (1966). Since then, its use in a wide variety of surgical procedures has been reported throughout the world. Several authors(Galloon, 1971; Gallon and Dick, 1971; Spoerel, 1971)reported that katamine has several advantages over conventional anesthetics. The advantages of using katamine anesthesia are: preservation of pharyngeal reflex and airway maintenance during induction of anesthesia, stimulation of the cardiovascular system, wide safety margin, short duration, fast recovery, little nausea and vomiting after anesthesia, little depression of the fetus and good uterine contraction with minimal bleeding. On the other hand, ketamine has also disadvantages: elevation of arterial pressure and pulse rate temporarily during induction of anesthesia, poor muscle relaxation and post-operative psychotic reactions are not uncommonly found. The authors tried to find out the feasibility of ketamine anesthesia for Cesarean section over the conventional method of thiopental muscle relaxant N₂O with IPPV technique. Materials and Methods. 52 Korean parturients were selected for Cesarean section including emergency and elective operation for this study. Thiopental Group. 25 cases were induced for anesthesia with 3.5±1.64mg/kg of thiopental and intubated with the help of 1 mg/kg of succinylcholine followed by N₂O with controlled ventilation. After delivering the baby, anesthesia was maintained with N₂O-O₂-ether throughout the procedures. Ketamine A Group. 9 cases, just before skin incision, were injected intravenously with katamine 1.67±0.03mg/kg slowly for over one minute with or without N₂O: O₂(2: 1 L/min) through a mask. After delivering the fetus, a supplement of ketamine and diazepam 10mg I.V. was given intermittently. Ketamine B Group. Anesthesia was induced by 1.72±0.05mg/kg ketamine and 1mg/kg of succinylcholine with endotracheal intubation. After delivery, N₂O with O₂ and additional ketamine were given to 9 patients. Ketamine C Group. Anesthesia was performed with 1. 30±0.15mg/kg of ketamine, 0.08mg/kg of pancuronium, N₂O, with endotracheal intubation for 9 patients, ether supplement was given following delivery .Conclusion .With these mentioned methods of anesthesia, the authors formed several conclusions about ketamine anesthesia in Cesarean section. 1. Ketamine can be used as the main anesthetic or for induction in elective and emergency Cesarean section because of its rapid onset and intense analgesic effect. 2. As in the method of anesthesia, it is useful to combine N₂O-O₂ mixture and muscle relaxants such as succinylcholine or pancuronium. This technique is more suitable for maintenance of anesthesia because of the poor muscle relaxation of ketamine alone. 3. For induction of anesthesia, under 1.6mg/kg of ketamine is advisable. Exceeding this dose, the infant respiration is more likely to be depressed because of hypertonicity of the skeletal musculature. 4. Ketamine has a maternal cardiovascular stimulation effect particularly diastolic blood pressure and pulse rate in the Ketamine-pancuronium-N₂O-intubation group. 5. Less bleeding was found during and after the delivery, possibly due to an increased uterine contraction from ketamine. 6. Disadvantages of ketamine included a prolonged maternal recovery period, and newborn respiratory depression end these seemed to be dose related. Fro the above, ketamine anesthesia appears to be another safe and satisfactory method of anesthesia for Casarean section, provided that toxema of pregnancy patients with hypertension and patients who have had psychotic problems previously are avoided.