Background: Scientific research regarding male-female differences in ascending aortic surgery is scarce. The objective of this study was to identify male-female differences in presentation, treatment and perioperative outcome in elective ascending aortic surgery. Methods: Elective ascending aortic surgery procedures that took place in the Netherlands between 01/01/2013-31/12/2017 were identified from the Netherlands Heart Registration. Male-female differences in presentation, treatment characteristics, and in-hospital mortality and morbidity were explored. Results: The study population consisted of 887 females (31%) and 1,972 males (69%). Females were older (median age 67 versus 62 years, P<0.001), more often had chronic lung disease (12.3% versus 9.1%, P=0.011), New York Heart Association (NYHA) class III-IV (21.5% versus 15.5%, P=0.003), and less often a history of percutaneous coronary intervention (PCI) (3.2% versus 5.0%, P=0.033). Isolated supracoronary aortic replacement was performed in 47.7% of females versus 30.6% of males (P<0.001), and ascending aorta with root replacement in 40.6% of females versus 56.7% of males (P<0.001). Females more often underwent concomitant interventions of the aortic arch (33.1% versus 20.2%, P<0.001) and the mitral valve (8.2% versus 5.2%, P=0.002), and less often concomitant coronary artery bypass grafting (CABG) (14.4% versus 19.1%, P=0.002). Overall, in-hospital mortality was significantly higher in females (5.1% versus 2.7%, P=0.003). In multivariable regression analysis, being female was an independent risk factor for in-hospital mortality [odds ratio (OR) 1.55, 95% confidence interval (CI): 1.02-2.37]. Conclusions: This nation-wide cohort shows clear differences between females and males in patient presentation, procedural characteristics, in-hospital outcomes, and risk factors for in-hospital mortality in elective ascending aortic surgery. Further exploration of these differences, and of modifiable within-male and within-female risk factors, may offer ...