The use of transoesophegeal echocardiography (TOE) in the operating room is now well established. Initially TOE was used mainly as a monitor of left ventricular ischemia, but now provides real-time dynamic information about the anatomy and physiology of the whole heart. TOE is of value in the management of patients undergoing procedures including surgery of the heart and great vessels; it is also useful in guiding therapy in haemodynamically unstable patients undergoing non cardiac surgery in the operating room The use of TOE carries not only the benefits of a rapid and effective investigation, but also risks associated with the procedure itself and the burden of providing training and experience for practitioners. The establishment of TOE in intra-operative cardiac anesthetic care can provide new information which may change the course and the outcome of surgical procedures.