Known for its reliability, transoesophageal echocardiography is an investigation which is increasingly used in cardiology, cardiac surgery and intensive care units. It is a semi-invasive investigation of which oesophageal perforation is a very rare but serious complication. Two cases of oesophageal perforation after transoesophageal echocardiography are reported out of a series of 87 oesophageal perforations treated between January 1981 and February 1999. In both cases, transoesophageal echocardiography was performed in conscious patients without known pre-existing oesophageal pathology. The presentations were acute. Both patients underwent emergency surgery. One patient is alive and the other one died one month after a second operation related to the perforation. Nine cases of oesophageal perforation have been reported after transoesophageal echocardiography. The pathogenesis, means of prevention and treatment of oesophageal perforation are discussed.