A total of 496 cases of infant surgery which were performed at Yonsei Medical Center from 1961 to 1970 were analyzed statistically according to sex, age, disease, anesthetic technique, anesthetics, post-op. complications, and mortality. These infants were all inpatients and were operated on under general anesthesia. The results were as follows: 1. Sex; 374 males far exceeded 122 females. 2. Age; 52.5% were in the 1~6 month age group. 3. Disease; Most common diseases in order were cleft lip (113 cases) intussusception (63 cases) and inguinal hernia (41 cases). 4. Anesthetic technique; Most cases used endotracheal intubation and non-rebreathing technique. 5. Anesthetics; Diethyl ether was mainly used (69.2%). 6. Complications; In 34 cases (6.85%) surgical and anesthetic complications occurred. 7. Mortality; 31 infants, 6.25% of the total cases, died during the operative and post-operative periods. 17 of these were 0~7 days old.