A 16-year-old boy who was involved in a motorcycle crash developed a severe chest injury associated with lumbar artery rupture due to blunt abdominal injury. The patient underwent emergent exploratory laparotomy for repairing the abdominal aorta, and he had an uneventful recovery. Blunt abdominal aortic trauma is potentially lethal if undetected at an early stage and if aggressive management is not adopted. Trauma surgeons should be aware of the possibility of the occurrence of aortic injury in unstable trauma patients.