OBJECTIVE To assess the usefulness of intraoperative transesophageal echocardiography (IOTEE) in a cardiac surgery department. METHODS Patients were examined with IOTEE before and after cardiopulmonary bypass. All studies were performed with a Toshiba 270 SSA model imaging device. All IOTEE examinations were performed by two cardiovascular surgery residents who are experienced in IOTEE. RESULTS A total of 466 patients (239 men, 227 women) were examined by IOTEE from 2001 through 2007. Of these 182 (39%) were performed during correction of valvular pathologies, 193 (41%) during coronary operations, 34 (7%) during combined operations (either valvular or coronary bypass), 8 (1.7%) in adult congenital heart operations, 7 (1.5%) in cardiac mass operations, and the rest in other miscellaneous operations. TEE examinations performed before and after the cardiopulmonary bypass influenced surgical decisions by 14.8% and 9.0%, respectively. Decisions regarding the mitral valve were the most frequent followed by decisions regarding the tricuspid valve. CONCLUSIONS IOTEE significantly affected decision making in cardiac surgery operating room. IOTEE examination must be a standard procedure for all patients undergoing cardiac surgery.