A 62 year-old man sustained esophageal perforation following intra-operative transesophageal echocardiography (TEE) in a valvular replacement surgery. Septic shock developed on the 12th postoperative day (POD) and the esophageal perforation was diagnosed with chest CT. Emergent operation together with intensive care saved the patient's life. We speculate that the mechanism of perforation was not due to manipulation of the probe, but rather due to ischemia of the esophagus resulting from the combination of probe compression, non-pulsatile flow and the distension of the atria during a lengthy procedure. It is advisable that in patients with operative risk factors, such as distension of atria, long cardiac procedure and likely ischemia of organs due to cardiopulmonary bypass, the monitoring probe of TEE should not constantly rest in the esophagus and be withdrawn when it is idle or not in actual use. In addition, if resistance has been met during the intraoperative manipulation of the probe in a patient without previous history of esophageal disease, perforation might suspected if he or she sustains postoperative fever with positive chest X-ray findings.