Background:The measurement of cardiac output is an essential part of anesthetic practice in patients undergoing liver transplantation. A thermodilution technique, using a pulmonary artery catheter is currently accepted as the gold standard in clinical practise. However, its use is associated with several limitations.Methods: An esophageal doppler monitor was compared with the thermodilution technique in 22 patients undergoing split graft transplantation from a living donor. Six measurement were taken during liver transplantation, 1) control, 2) dissection phase, 3) anhepatic phase, 4) reperfusion phase, 5) after hepatic artery anastomosis, and 6) end of surgery.Results: Significant difference were observed between the two measurement at all times studied with a strong correlation, except at the end of surgery (r ＞ 0.4).Conclusions: The use of esophageal doppler monitor results in cardiac output measurements which are considerably different from those obtained using thermodilution, but a strong correlation exists between two methods. Thus the use of esohageal monitoring can be recommended in patients undergoing liver transplantation for trend monitoring.