This retrospective, observational study was performed on adult patients undergoing thoracic aortic surgery (ATAS) requiring standardized deep hypothermic circulatory arrest (DHCA) with following aims. (1). To determine the mortality rate after ATAS-DHCA (2). To determine univariate predictors for mortality after ATAS-DHCA (3). To determine multivariate predictors for mortality after ATAS-DHCA A total of 144 patients operated during 2000/2001 were included. The mortality rate was 11.1%. Univariate predictors for mortality after ATAS-DHCA were preoperative ejection fraction less than 40%, stroke, packed red blood cell transfusion within first 24 hours, sepsis, mediastinal re-exploration for bleeding within first 24 hours, and renal dysfunction. Multivariate predictors for mortality after ATAS-DHCA were sepsis (odds ratio 21.3:1; confidence interval 3.8-12.1; p=0.001), postoperative stroke (odds ratio 7.4:1; confidence interval 1.9-28.7; p=0.004) and mediastinal re-exploration within first 24 hours (odds ratio 7.7:1; confidence interval 1.3-45.1; p = 0.02) We conclude that mortality after ATAS-DHCA remains high. The identified multivariate predictors merit further hypothesis-driven intervention.