BACKGROUND: Female patients with infective endocarditis (IE) are referred to surgery less often than male patients, and research on sex differences after IE surgery is inconclusive. Understanding the impact of sex can help clinicians optimize patient care. Therefore, we investigated sex-based differences in loss of life expectancy and net survival after aortic valve surgery for IE. METHODS: We conducted a population-based, observational cohort study, including all patients undergoing aortic valve surgery for IE in Sweden from 1997 to 2022. Data came from national registers, including SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart-Disease Evaluated According to Recommended Therapies). Loss of life expectancy and net survival were calculated based on population data from the Human Mortality Database. Flexible parametric models were used to assess net survival. RESULTS: A total of 2585 patients underwent aortic valve surgery for IE; 19% were female. Women were older than men (median age 66 versus 63) and had more concomitant valve surgery and comorbidities, as well as lower socioeconomic status. During a mean follow-up of 7 years, 245 female patients (49%) versus 857 male patients (41%) died. Loss of life expectancy was accentuated in younger patients, ranging from 15.5 years (95% CI, 9.0-21.9) in a 50-year-old female to 2.1 years (95% CI, 0.95-3.2) in an 80-year-old male. After regression standardization, women had higher net survival compared with men. CONCLUSIONS: After aortic valve surgery for IE, net survival was higher among female patients after accounting for baseline differences, and loss of life expectancy was considerable for both female and male patients, particularly in younger patients. Focus on early diagnosis, as well as optimized pre- and postoperative care, is essential in patients with IE.