Thirty-day and 1-, 5-, 10-, and 20-year overall survivorships among 82 patients undergoing replacement of the ascending aorta with or without the arch for acute aortic dissection between 1968 and May 1989 were 79%, 66%, 56%, 46%, and 30%, respectively. The multivariably determined risk factors for death were the inclusion of the arch in the replacement, the year of the operation, the predissection New York Heart Association functional class, diabetes, and concomitant coronary artery bypass grafting. The current 30-day survivorship predicted by the multivariable equation when the operation involves only the ascending aorta is 97%, and the 10- and 20-year predicted survivorships are 61% and 39%, respectively. When the current era the replacement involves the arch as well as the ascending aorta, the predicted 30-day survivorship is 84%, and the 10- and 20-year ones are 48% and 31%. In 1990 sixteen additional patients (one hospital death) underwent ascending aortic replacement, and six (no hospital deaths) ascending aorta and arch replacement. The predictions for 1990 from the multivariable equation were similar to these actual experiences (Ps for differences were 0.6 and 0.4). Seventy percent of surviving patients with DeBakey type I dissection were free of a second aortic operation for aneurysmal dilation of the distal false channel, but this occurred in none of nine patients in whom an intimal tear in the transverse arch was included in the resection.