OBJECTIVE: To assess the diagnostic potential of transthoracic and transoesophageal echocardiography for the detection of traumatic cardiovascular injuries in patients suffering from severe blunt chest trauma. DESIGN: Prospective study over a three year period. SETTING: A regional cardiothoracic centre. PATIENTS: 134 consecutive patients (94 M/40 F; mean age 38 (SD 14) years) suffering from severe blunt chest trauma (injury severity score 33.5 (18.2)). Most patients (89%) were victims of motor vehicle accidents. EVALUATION: All patients underwent transthoracic and transoesophageal echocardiography within 8 h of admission. Aortography was performed in the first 20 patients and in a further five equivocal cases. RESULTS: Transthoracic echocardiography provided suboptimal images in 83 patients, detecting three aortic ruptures, 28 pericardial effusions (one cardiac tamponade), 35 left pleural effusions, and 15 myocardial contusions. Transoesophageal echocardiography was feasible in 131 patients and detected 14 aortic ruptures (13 at the isthmus), 40 pericardial effusions, 51 left pleural effusions, 34 periaortic haematomas, 45 myocardial contusions, right atrial laceration in one patient with cardiac tamponade, one tricuspid valve rupture, and one severe mitral regurgitation caused by annular disruption. For the detection of aortic rupture transoesophageal echocardiography showed 93% sensitivity, 98% specificity, and 98% accuracy. Time to surgery was significantly shorter (30 (12) v 71 (21) min; P < 0.05) for patients operated on only on the basis of transoesophageal echocardiographic findings. CONCLUSIONS: Transthoracic echocardiography has low diagnostic yield in severe blunt chest trauma, while transoesophageal echocardiography provides accurate diagnosis in a short time at the bedside, is inexpensive, minimally invasive, and does not interfere with other diagnostic or therapeutic procedures.