Background: Differences in cardiac remodeling after mitral valve (MV) surgery between the sexes is poorly understood. Inferior outcomes for females undergoing MV surgery compared to males have been suggested in the literature, although causative factors behind this discrepancy have not been identified. Materials and Methods: In this propensity-matched, retrospective, singlecenter study, we sought to identify the impact that sex may have on cardiac remodeling and long-term outcomes to better inform clinical decision making in MV surgical intervention. Outcomes were compared between males and females undergoing MV replacement (MVR) between 2004 and 2018. The primary outcome was cardiac remodeling 1 year postoperatively. Secondary outcomes included mortality, stroke, myocardial infarction (MI), reoperation of the MV, and rehospitalization. Results: 314 males and 314 females were included after propensity matching. Males demonstrated a significant degree of improved left ventricular remodeling while females did not, and females showed a significant degree of left atrial remodeling while males did not. Mortality rates were relatively equivalent between the two groups, although males were more likely to develop sepsis and require rehospitalization due to MI. Conclusions: There has been little research exploring the differences in cardiac remodeling between the sexes after MVR. The results of this study have suggested that MVR is equally safe for both sexes and has demonstrated a difference in the heart's ability to remodel after MVR. The significance of this difference has the potential to result in largely different clinical outcomes for males and females. Further study is necessary to fully elucidate this relationship.