Blunt injuries to the ascending aorta and branches of the aortic arch are unusual but must be considered in any victim of a high speed decelerating injury. Because there are no characteristic clinical or roentgenographic findings, aortography is the only definitive method of establishing the diagnosis. Aortography should therefore, be performed upon any patient who has had a high speed decelerating injury, regardless of the clinical or the roentgenographic findings. An early operation will prevent exsanguination.