['The management of type A intramural hematoma (IMH) is controversial. Although most Western countries still recommend immediate surgical repair, some centers in Asia have shown good results recently with medical treatment alone. Here, we present a case of type A IMH which was discovered during the operation to be a thrombosed type A dissection.', 'An 83-year-old female patient presented with acute chest pain. After diagnostic exclusion of myocardial infarction, computed tomography was performed, which showed an IMH from the ascending to the descending aorta. No intimal flap could be detected. The ascending aorta was replaced surgically with a prosthesis. During the operation, we found a ruptured intimal plaque, which had caused dissection of the aorta with thrombosis of the false lumen. The true diagnosis-thrombosed type A dissection and not IMH-was revealed neither by computed tomography nor by transesophageal echocardiography.'] Does type A intramural hematoma often turn out to be a type A dissection?