Acute aortic dissection is a rare but potentially fatal disease. The early recognition of this disease is important for timely treatment. Some signs and symptoms, such as past history of hypertension, tearing pain, and pulselessness, can provide valuable clues to the diagnosis of this disease. In this case study, the mechanism of a seagull murmur from aortic dissection is first described. This information is potentially useful for the differential diagnosis of dissection.