Acute aortic dissection is rare but potentially life-threatening disease with an incidence of 5-30 cases per million, annually. Therefore prompt diagnosis is crucial. D-dimer values have been shown to be useful in the diagnosis of acute aortic dissection. Fibrinogen levels have been shown to be low, normal or high in individuals with acute aortic dissection. This study aims to investigate whether D-dimer/fibrinogen ratio can be valuable for diagnosis of acute aortic dissection.