Between March 1982 and June 1992, 17 patients (age: 21-76 years) were diagnosed with pseudoaneurysm of the thoracic aorta (PTA). Four PTAs developed post-trauma while 13 developed after aortic or cardiac surgery. Unusual presentations included: dyspnea, hoarseness, dysphagia, massive hemoptysis (2 degrees to aortobronchial fistula), massive hematemesis (2 degrees to aorto-esophageal fistula), superior vena cava syndrome, paralyzed right hemidiaphragm, and herald bleeding from the sternotomy. The interval between initial operation and recognition of PTA varied from three months to eight years while the four posttraumatic PTAs presented 5 to 26 years postinjury. The sites of postoperative PTA were: the aortotomy (3), proximal vein graft anastomosis (4), aortic cannulation site (2), and distal anastomosis of ascending aortic graft replacement (4). Aortography was very sensitive, outlining the false aneurysm in 13/13. Five patients had transesophageal echo-cardiography with one false negative. Seven patients died (41%), three from postoperative PTAs from massive hemorrhage intraoperatively and four from sepsis and multiorgan failure following repair. We conclude that patients who have previously had aortic or cardiac surgery or a history of blunt chest trauma presenting with unusual cardiorespiratory symptoms should be aggressively evaluated for PTA. Due to the magnitude of the operative problems encountered, repair of PTA is associated with a significantly high rate of mortality.