An 80-year-old male patient(160 cm, 52 kg) underwent a combined coronary artery bypass graft and aortic valve replacement. He had no history of gastric or esophageal disease. Transesophageal echocardiography(TEE) was used for an intraoperative monitor. At the end of surgery, massive fresh blood was aspirated through a gastric tube after removal of the TEE probe. An urgent esophago-gastroduodenoscopy and computed tomography diagnosed a gastric perforation, for which the patient had to undergo an urgent laparoscopic repair. The surgical repair was successful and the patient was discharged on the postoperative day 21.