Background: Left ventricular (LV) hypertrophy caused by aortic valve stenosis (AS) leads to cardiovascular morbidity and mortality. We sought to determine whether aortic valve replacement (AVR) decreases LV mass and improves LV function. Materials and Methods: Retrospective review for 358 consecutive patients, who underwent aortic valve replacement for degenerative AS between January 1995 and December 2008, was performed. There were 230 men and 128 women, and their age at operation was $63.2{pm}10$ years (30~85 years). Results: There was no in-hospital mortality, and mean follow-up duration after discharge was 48.9 months (2~167 months). Immediate postoperative echocardiography revealed that LV mass index and mean gradient across the aortic valve decreased significantly (p<0.001), and LV mass continued to decrease during the follow-up period (p<0.001). LV ejection fraction (EF) temporarily decreased postoperatively (p<0.001), but LV function recovered immediately and continued to improve with a significant difference between preoperative and postoperative EF (p<0.001). There were 15 late deaths during the follow-up period, and overall survival at 5 and 10 years were 94% and 90%, respectively. On multivariable analysis, age at operation (p=0.008), concomitant coronary bypass surgery (p<0.003), lower preoperative LVEF (<40%) (p=0.0018), and higher EUROScore (>7) (p=0.045) were risk factors for late death. Conclusion: After AVR for degenerative AS, reduction of left ventricular mass and improvement of left ventricular function continue late after operation.