Background: Aortic valve replacement (AVR) improves left ventricular (LV) systolic function in patients with chronic aortic regurgitation (AR). The objective of this study is to determine predictors for normalization of impaired LV systolic function after valve replacement for chronic AR. Methods and Results: Between 1997 and 2007, 171 patients underwent AVR for severe chronic AR. Of these patients, 79 patients with LV systolic dysfunction or severe LV dilatation preoperatively, who were evaluated by echocardiography at predischarge and early follow up (mean, 6 months) were examined. The mean preoperative ejection fraction was 49%. The mean LV end-systolic and end-diastolic dimensions were 52.32±8.35mm and 69.59±7.80mm, respectively. In the early follow up, 62 of 79 patients exhibited restored normal LV function. LV end-systolic dimension and LV end-diastolic dimension were significantly decreased early after AVR (52.32±8.35mm vs 37.82±6.88mm, and 69.59±7.80mm vs 51.55±6.40mm, respectively). Operative mortality was 3.7%. Multivariate stepwise regression analysis revealed that preoperative indexed LV end-systolic and end-diastolic dimensions were independent predictors of restored LV systolic function. The sensitivity and specicity in predicting normalization of LV function were 88% and 92% for indexed LVESD <35.32mm/m² and 71% and 86% for indexed LVEDD <44.42mm/m². Conclusions: In patients who received a valve replacement for chronic AR, smaller indexed LV systolic and diastolic dimensions were associated with early restoration of LV systolic function. (Circ J 2010; 74: 2340-2345)