Anastomoses of the coronary buttons are the Achilles’ heel of the modified Bentall procedure (MBP) for the repair of the aortic root and ascending aorta. We present a rare case of post-MBP right coronary artery button pseudoaneurysm in a 30-year-old man. The contained leak, attributed to a pseudoknot in the polypropylene suture, was visualized via computed tomography angiography and transesophageal echocardiogram and repaired under deep hypothermic circulatory arrest.