Pseudoaneurysm of the ascending aorta is an unusual and potentially fatal complication of cardiovascular surgery. Most pseudoaneurysms are associated with aortic valve or coronary artery bypass graft surgery and are often mycotic in origin. Chest roentgenography and aortography have been the principle methods of diagnosis. Recently, contrast enhanced computed tomography (CT) has proven to be a useful means of diagnosis, providing a less invasive method of distinguishing pseudoaneurysm from other causes of fever and mediastinal widening in the postoperative cardiovascular patient. Thirty one cases of postoperative pseudoaneurysm of the ascending aorta occurring since 1963 are reviewed, including seven cases from our experience.