To evaluate the role of intraoperative transesophageal echocardiography (IOTEE) during surgical removal of cardiac masses, we studied 75 consecutive patients (34 men, aged 56 +/- 16 years, range 17 to 82 years) who underwent surgery primarily for cardiac mass removal with the adjunct of IOTEE for the years 1993 through 1998. The IOTEE provided new information before bypass in 6 patients (8%), altering the planned surgical procedure in all. A newly discovered patent foramen ovale was closed in 2 patients, a second myxoma discovered in one patient, a mitral valve repaired in one patient, inferior vena caval cannulation site clarified in one patient, and in one patient the mass was no longer present and the surgery canceled. In 10 patients (13%), new post-bypass information was found, which prompted return to bypass for valve repair in 3 patients, altered nonsurgical management in 3 patients, and did not necessitate specific measures in 4 patients. Thus, in 75 patients coming to surgery for mass removal, IOTEE affected intraoperative management in 12 (16%).