We present a case of intraoperative dissection of the aortic root in a patient with non-calcified aortic valve incompetence. This complication led to life-threatening bleeding from the dissection line into the layers of the left ventricle as well as the aortic wall with formation of an increasing subadventitial hematoma. The only possible management was to remove the valve prosthesis and to close the entry site of the dissection when reinserting the valve implant. The mechanism of this complication is discussed.