Aortic injuries can easily be missed in polytraumatized patients due to either associated injuries or vagueness of physical examination findings. Especially in young adults without associated injuries, relatively low atherosclerotic changes may limit the dissection of traumatic descending aortic injuries. We present a 34-year-old male patient who only had a complaint of back pain following a traffic accident. Upon detection of no abnormalities on plain X-ray films, he was discharged home with analgesics. One week later, he presented with dypsnea and dysphagia. Aortography showed rupture of the aorta and a pseudoaneurysm near the isthmus. Following surgical excision of the pseudoaneurysm and aortic repair with a Dacron graft interposition he was discharged with complete relief of symptoms. This case emphasizes the need for a high index of clinical suspicion in timely diagnosis and prompt treatment of traumatic aortic ruptures.