Intramural hematoma of the aorta is a condition increasingly observed in clinical practice. Uncertainty exists whether such lesions represent a different pathology or simply the precursors of classic dissecting aneurysm. The patient was a 76-year-old woman with intramural hematoma of the ascending aorta. Clinical course, progression of the lesion to type A aortic dissection, and surgical treatment are described. Although natural history of intramural hematoma of the ascending aorta is not clearly elucidated, the case presented confirms that the evolution toward intimal flap formation is possible and that we cannot foresee the stabilization of these lesions. We stress that intramural hematoma of the ascending aorta has to be managed as an aortic type A dissection and that aggressive treatment is advisable.