A man aged 26 was admitted after a traffic accident. The chest X-ray showed widening of the mediastinum without rib or sternal fractures. Therefore an aortogram was made which showed an avulsion of the aortic valve and a rupture of the left common carotid artery. The aortic valve was repaired by suturing and the carotid artery reimplanted into the left subclavian artery. Blunt chest trauma is becoming more common. If there is widening of the mediastinum on the chest X-ray an aortogram should be made. In this way the diagnosis, rupture of the thoracic aorta or of one of the aortic arch branches, and traumatic valve rupture can be made. Early diagnosis can be life saving.