Neonates requiring anesthesia present unique challenges for anesthesiologists. They are very different from children and adults in the point of anatomy, cardiovascular response, respiratory system, central and autonomic nervous system, renal system and fluid balance, metabolism and thermal homeostasis, and pharmacology. In addition, they are frequently associated with congenital anomalies. The object of this study is to analyze the neonates' operation and anesthesia and to improve the outcome. We analyzed the 428 neonates who had received operation from 1979 to 1992 retrospectively. We devided them into four groups by age ; 0-1, 1-2, 2-3, and 3-4 weeks old group, and 0-1 week group is subdivided into preterm and full term one. The results were as follows ; 1. The rate of male versus female was 2.2: 1 (68.7: 31.3%) and 54.2% of them had been operated under 1 week old age. 2. The incidence of operated diseases is in order of congenital megacolon (15.9%), imperforate anus (15.9%) and pyloric stenosis (10.5%). 3. Operating time was within 2 hours in almost cases (95.7%) except tracheo-esophageal fistula (141.82±43.49 minutes). And the disease having operated in the shortest duration was inguinal hernia (19.29±16.15 minutes). 4. Patients with duodenal atresia, gastroschisis, omphalocele, diaphragmatic hemia, and tracheo -esophageal fistula were somewhat associated with congenital anomalies and the mortality was 10.5 to 33.3%. 5. Endotracheal intubation was achieved by mask inhalation in 76.4% and remains by using intravenous drugs. 6. There was not used any neuromuscular blocking agents thorough the operation procedure in 133 cases (48.4%). 7. Breathing circuit for anesthesia was Mapleson F system in all and the airway was kept with endotracheal tube (91.3%), mask (5.1%), and laryngeal mask airway (3.6%). 8. There were about 40% of patients with tracheo-esophageal fistula, sacrococcygeal anomalies, diaphragmatic hernia, omphalocele, and gastroschisis requiring special respiratory care, that is, keeping endotracheal intubation and ventilator for certain postoperative period. 9. Overall rate of emergency operation was 61%, but it was 73% in 0-1 week old neonates. 10. Mortality of operation for neonates was 7.7% and it occurred mainly in the pateints with gastroschisis, omphalocele, duodenal atresia, diaphragmatic hernia, imperforate anus, and tracheo- esophageal fistula. But there was only 1.6% mortality during 24 hours after operation. With the above results I suggested that shortening of operation time and skilled anesthesia could markedly improved the outcome of operation for neonates. And to achieve the goal all neonatal surgeons and anesthesiologists will have to get many experiences and knowledge about the neonate pathophysiologic conditions and pharmacologic responses.