Background: Sex disparities in cardiovascular disorders are well documented, but data on in-hospital outcomes for Complete Heart Block (CHB) remain scarce. Using a national readmissions database, we assessed the association of sex with the outcomes of CHB cases. Methods: We examined the 2016-2020 Nationwide Readmission Database (NRD) to identify patients with a principal diagnosis of CHB. Men were used as our control group, while women comprised our cohort. The primary outcome was mortality. Secondary outcomes included odds of mechanical ventilation use, all cause 30-day readmission, length of stay (LOS) and total hospitalization charges (THC). Multivariate linear and logistic regression models were used to adjust for confounders. Results: Among the patients with CHB (N = 175,257), 45% were Female. A Female sex was associated with higher odds of mortality (adjusted OR aOR 1.42, 95% CI 1.3 – 1.55, p<0.001) compared to male patients with CHB. Additionally, female sex was associated with a higher likelihood of mechanical ventilation use (aOR 1.1, 95% CI 1.03 – 1.2, p=0.004), all cause 30-day readmission (aOR 1.08, 95% CI 1.03 – 1.13, p=0.004), longer LOS (4.13 days vs 3.86 days, p<0.001) and lower THC ($89,908 vs. $94,590, p=0.002) compared to male patients with CHB. Conclusions: Among patients with CHB, female sex was associated with higher odds of mortality and non-fatal adverse events compared to male patients.