The Authors present a case of thoracoabdominal trauma from a road accident in a young woman who received care initially in a level II hospital. She was then transferred to a level I Trauma Centre with the onset of haemorrhagic shock due to haemopericardium and haemoperitoneum from liver injuries. A chest CT scan led to the suspicion of aortic dissection, hence a cardiopulmonary bypass (CPB) for life support was instituted just before laparotomy through the femoral vessels. Exploration of the peritoneal cavity was performed as a first step because haemoperitoneum was deemed to be the main cause of shock. One litre of blood was aspirated and hepatosplenic tears were sutured to obtain haemostasis. Subsequently, aortic dissection was ruled out by median sternotomy, while a right atrial disruption was identified and repaired by stitches and a pericardial homologous patch. Nevertheless, the ascending aorta was explored by transverse arteriotomy. The postoperative course was uneventful and the woman has never presented cardiac or abdominal symptoms as a result of trauma or surgery.