We describe the case of a 46-year-old female patient, who was referred to us under the suspicion of an acute type-A aortic dissection. After perusal of the computer tomogram and subsequent transesophageal echocardiography, we decided to operate, albeit under the assumption of the existence of a pericardial cyst. Intraoperatively a strikingly large aneurysm of the right coronary artery presented itself, which was successfully treated through resection and end-to-end anastomosis.