Transoesophageal echocardiography (TOE) is increasingly used in cardiology, cardiac surgery and intensive care. Its complications are rare. We report a case of perforation of the oesophagus after TOE in a 71-year-old woman, scheduled for an elective aortic valve replacement. Her medical history included arterial hypertension but no pre-existing oesophageal disease. A Hewlett Packard ultrasound imaging system was used, with a 5 MHz single plane probe. After local anaesthesia, the transducer probe was inserted into the distal oesophagus, after three attemps, without any apparent incident. A few hours later, the patient complained of acute cervical and dorsal pain. Examination showed severe skin emphysema in of neck, but neither breathing difficulties, nor haemodynamic modifications. The EKG was normal and body temperature at 38.8 degrees C The opacification of the oesophagus showed a passage of the constrast medium into the mediastinum. Emergency surgical exploration by left cervicotomy showed a perforation of 2 to 3 cm of the posterior wall of oesophagus, treated with terminal oesophagostomy and drainage. The pressure by the TOE probe on the oesophagus may explain this perforation. The outcome was uneventful. Although TOE is a semi-invasive technique with a low risks its benefit/risk ratio should be considered in each patients before using it.