Both aortic dissection and aortic aneurysm are complicated with disseminated intravascular coagulation (DIC) at the rate of four percent. DIC is said to be caused by the imbalance between coagulation and fibrinolysis and is classified into three types : suppressed fibrinolysis, balanced fibrinolysis, and enhanced fibrinolysis. Tranexamic acid has effects on suppressing the fibrinolytic system by inhibiting the mechanism by which plasmin decomposes fibrin. It is generally considered that the use of tranexamic acid for DIC is contraindicated. However, some reports show its effectiveness for non-infective chronic DIC. We illustrate two cases of DIC with enhanced fibrinolysis which are complicated with aortic dissection or aortic aneurysm that were successfully treated with tranexamic acid.