Objective: Predictors for post-operative reverse remodeling in patients with severe aortic regurgitation (AR) and reduced left ventricular ejection fraction (LVEF) are unknown. We performed low-dose dobutamine stress echocardiography (DSE) in patients with severe AR and reduced LVEF to evaluate the relationship between contractile reserve (CR) and reverse remodeling after surgery. Methods: In 31 patients with chronic severe AR and reduced LVEF (LVEF < 50%), we performed pre-operative DSE, assessed CR and examined whether changes in preoperative DSE were associated with improvement of post-operative LVEF after aortic valve surgery. Results: The pre-operative echocardiographic findings were as follows: left ventricular (LV) end-diastolic dimension: 67 ± 10 mm, LV end-systolic dimension: 52 ± 13 mm and LVEF: 42% ± 8%. All patients underwent aortic valve surgery. Patients with pre-operative LVEF of >45% exhibited a significant increase in LVEF; however, patients with pre-operative LVEF of <45% showed no significant change. When we examined the results of DSE performed in patients with pre-operative LVEF of <45%, ΔLVEF of ≥6% (with CR) during DSE was related to an improvement in post-operative LVEF; ΔLVEF of ≥6% during DSE predicted an improvement in post-operative LVEF, with a sensitivity and specificity of 80% and 85%, respectively. Conclusions: DSE may be a helpful tool for predicting post-operative reverse remodeling in patients with severe AR and moderately reduced LVEF.