Breech presentatiion is the most frequent abnormal presentation And excessive perinatal loss is asdsociated with brecch presentation and in large measure this loss in accounted for by prematurity congenital anomalies and birth traums In the endeavor to exert an effect on two of these problems cesarean section has been resorted to increasingly This study was analyzed the 375 singleton breech rpesentations among the total 9,267 deliveries retrospectively by the review of the charts which occrued during the period from January 1979 to December 1983 at In Je Medical College Pail Hospital in Seoul Department of Obstetrics and Gynecology and discussed the various aspects and diffculties in their managements This paper obtained the following results: 1. The incidence of the breech presentation was 4.05%(1:25) 2. The age distribution was mostly concentrated between the age of 26 and 30 (52.5%). 3. Incidence of the breech delivery by parity was 4.68% in primpara and 3.07 % in multipara. 4. As to gestational weeks, the frequency was mostly concentrated between 37 and 39 weeks (56.3%), and 31.7% between 40 and 42 weeks, 3.5% between 34 and 36 weeks, and less than 29 weeks, 2.9% between 29 and 33 weeks, and 2.1% in more than 42 weeks in orders. 5. the frank breech incidence was 33.3%, incomplete breech incidence was 28.8%, and complete breech incidence was 22.4%. 6. yearly cesarean section rate was from 55.1% to 75.4, and the mean was 67.5%. 7. Incidence of cesarean section by parity was 74.6% in primipara, 50.7% in first multipara, 45.8% in second multipara, and 37.5% in third multipara. 8. As to the birth weight, the frequency of cesarean section was mostly concentrated between 3,000 and 3,500gm(78.6), and 71.4% between 3,500 and 4,000gm 63.2% in more than 4,000gm, 67.0% between 2,500 and 3,000gm, and 56.3% between 2,000 and 2,500gm in orders, but none of the group less than 2,000gm. 9. As to the prognosis of the infants estimated by Apgar score, the depression rate of the infants by vaginal delivery was 6 times more higher than that of cesarean section delivery if the birth weight was over 2,000gm. 10. The perinatal mortality was 117.3/1,000, and the cause of death was prematurity, congenital anomalies, intracranial hemorrhage, entrapped aftercoming head, and cord prolapse in orders.