Disseminated intravascular coagulation (DIC) is an acquired coagulation disorder that occurs when the normal hemostatic balance is disturbed, primarily by excessive thrombin formation. Moreover, while DIC is a rare complication of aortic dissecting aneurysm, it is also a well-recognized one. We reported a case of DIC associated with aortic dissecting aneurysm in a 55-year-old woman who was transferred from another hospital because of chest pain radiating to her back and thrombocytopenia. Laboratory findings showed DIC with severe thrombocytopenia, and she was diagnosed as having an acute aortic dissection and DIC. After medical treatment on the aortic dissecting aneurysm, her DIC profile recovered.