Background: Left ventricular (LV) remodeling after patent ductus arteriosus (PDA) closure and predictors of LV systolic function late after the closure remain to be clearly demonstrated. Methods: In 72 patients with PDA (age: 42짹13 years) including 35 patients who received successful occlusion using Amplatzer device (AD group) and 37 who received surgical closure (OP group), LV end-systolic volume, end-diastolic volume and ejection fraction were measured using echocardiography before closure and 1 day (AD group) or within 7 days (OP group) after closure, and then followed up for 21짹26 months. LV volumes were standardized by body surface area of each patient. Results: In both groups, LV ejection fraction and end-diastolic volume index were significantly decreased immediate after closure, while end-systolic volume index did not change. Post-closure deterioration of ejection fraction in AD group was smaller than that in OP group (-7짹7 vs. -18짹10 %, p<0.05). After long-term follow-up, end-systolic volume index decreased significantly, but ejection fraction remained to be low compared to pre-closure state in both groups, although it was recovered from immediate post-closure state. In all 72 patients, follow-up LV ejection fraction negatively correlated with end-systolic (r=-0.62, p<0.001) and end-diastolic volume indices (r=-0.33, p<0.05), and positively with ejection fraction (r=0.67, p<0.001) of pre-closure state. Pre-closure LV ejection fraction was the only independent determinant of follow-up ejection fraction by multiple stepwise regression analysis (p<0.001). Pre-closure ejection fraction ��� 62 % predicted follow-up normal LV ejection fraction (��� 50%) with sensitivity 73 % and specificity 83 %. Conclusion: LV end-diastolic volume decreases early and end-systolic volume decreases late after PDA closure. LV ejection fraction before closure is the best index to predict late post-closure LV ejection fraction.