A traumatic aortic injury due to blunt chest trauma is well recognized. However, a delayed death due to an aortic laceration after blunt chest trauma is very rare. A 49-year-old man arrived at the emergency room after falling from a height of approximately 4 m. Upon radiological examination, multiple fractures to his left ribs with a hemopneumothorax on his left side were found. After undergoing a closed thoracostomy, he was admitted to the general ward due to his vital signs being stable. After 13 hours from his admission, he complained of chest discomfort with the sudden development of massive blood drainage through his chest tube. A cardiopulmonary resuscitation was performed, where the patient then died and an autopsy was performed 36 hours after his death. On internal examination, a small laceration of the descending aorta with irritation of the tunica adventitia was revealed. Given the findings of an additional histological examination and the aforementioned findings, the author thought that the fractured fragments of the posterior ribs had irritated the tunica adventitia of the adjacent descending aorta for some time after the chest trauma and that a perforation had finally occurred. The author here reports a case of a delayed death due to an aortic laceration after a blunt chest trauma with the patient's clinical information and full autopsy findings.