Haematoma of the thoracic aortic wall is a relatively new concept, the physiopathology of which remains controversial. It results from an haemorrhage of the aortic wall due to rupture of the vasa-vasorum without communication with the arterial lumen. This is a diagnosis of elimination of dissection of the aorta which has been made possible by modern techniques of imaging, such as transoesophageal echocardiography, helicoidal scanner and magnetic nuclear resonance imaging. The prognosis of haematoma of the aortic wall is not as bad as that of dissection of the aorta. Recent studies have shown that the condition may stabilise, regress or progress towards complications of two types: early, dissection or fissuration of the aorta, and late, aortic aneurysm. This is a medico-surgical emergency, the treatment of which is not well codified. However, schematically, haematoma of the aortic wall should be managed in the same way as dissection of the aorta: surgery when the ascending aorta is affected, medical treatment in other cases in the absence of complications.