BACKGROUND: Limited data exist on sex differences in guideline-recommended statin therapy for secondary prevention after coronary artery bypass surgery (CABG). We examined sex differences in statin use after CABG and the association between sex-specific statin use and mortality. METHODS AND RESULTS: Data from the Austrian national cardiac surgery registry and federal social insurance claims database for patients who underwent CABG between 2013 and 2021 were used. Multivariable logistic regression models were calculated to obtain women-to-men odds ratios for filling any statin and high-intensity statin prescriptions. Cox proportional hazards models were used to evaluate the association between statin use and mortality. A total of 15 448 patients (19% women) were included. During the 5 years after CABG, statin use decreased from 95.7% to 85.9% in men and 95.2% to 84.3% in women (P for trend <0.0001; P_int=0.48), high-intensity statin use decreased from 69.4% to 57.2% in men and 67.8% to 54.3% in women (P for trend <0.0001; P_int=0.59). The adjusted odds ratio for filling any statin prescription comparing women with men was 1.03 (95% CI, 0.92-1.16) and for filling a high-intensity statin prescription was 1.12 (95% CI, 1.02-1.23). Statin use was associated with a significantly lower mortality risk in both sexes (any statin: hazard ratio [HR], 0.56 [95% CI, 0.46-0.68]; P<0.0001, P_int=0.22; high-intensity statin: HR, 0.52 [95% CI, 0.42-0.63]; P<0.0001, P_int=0.48). CONCLUSIONS: Women were as likely as men to fill a statin prescription after CABG and more likely to fill a high-intensity prescription. Statin use was associated with a similar mortality risk reduction among women and men.