BACKGROUND: It is well known that cardiac output increases the greatest after a normal vaginal delivery. This study was to demonstrate the change of cardiac output after delivery by a cesarean section. METHODS: Eighty three women who underwent an elective cesarean section were involved in this study. They were anesthetized with enflurane, O2 and N2O (1:1) after injection of glycopyrrolate IM as a premedicant. Hemodynamic variables (CO, CI, SVR, SVRI, SI, EF, MAP and HR) were measured at three different time points; preoperation, 10 and 30 minutes after delivery by using a thoracic bioimpedence. RESULTS: The values of CO, CI, SI, and EF at 10 and 30 minutes after delivery were increased significantly (P< 0.05) compared to those of preoperation. The CO of 10 and 30 min after delivery increased 35.4% and 30.7% retrospectively. However, the values of SVR and SVRI were decreased significantly (P< 0.05) and the values of MAP and HR were not changed at 10 and 30 minutes after delivery when compared to those of preoperation. CONCLUSIONS: From these result, the CO after delivery during a cesarean section under enflurane anesthesia increased significantly. Therefore, decompensation in the early postpartum period is a risk in patients with compromised cardiac status.