The aim of this study was to evaluate the prognostic impact of left ventricular ejection fraction (LVEF) in patients with severe aortic stenosis (AS). The prognostic impact of LVEF in severe AS remains controversial. Among 3,815 consecutive patients with severe AS enrolled in the CURRENT AS (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis) registry, the present study population consisted of 3,794 patients after excluding 21 patients without LVEF data. Patients were divided into 4 groups according to LVEF at index echocardiography (<50%, 50% to 59%, 60% to 69%, and ≥70%; conservative strategy: n = 388, n = 390, n = 1,025, and n = 800; initial aortic valve replacement strategy: n = 206, n = 170, n = 375, and n = 440). Echocardiographic data were site reported, and there was no echocardiography core laboratory. In the conservative group, the cumulative 5-year incidence of the primary outcome measure (a composite of aortic valve-related death or heart failure hospitalization) was significantly higher in patients with LVEFs <50% and 50% to 59% than in those with LVEFs 60% to 69% and ≥70% (72.3%, 58.4%, 38.7%, and 35.0%, respectively, p < 0.001), whereas in the initial aortic valve replacement group, the negative effect of low LVEF was markedly attenuated (20.2%, 20.3%, 17.7%, and 12.4%, respectively, p = 0.03). After adjusting for confounders, LVEF <50% (hazard ratio: 1.82; 95% confidence interval: 1.44 to 2.28; p < 0.001) and 50% to 59% (hazard ratio: 1.77; 95% confidence interval: 1.42 to 2.20; p < 0.001) but not 60% to 69% (hazard ratio: 1.14; 95% confidence interval: 0.94 to 1.39; p = 0.17) were independently associated with poorer outcomes compared with LVEF ≥70% (reference) in the conservative group. In the initial aortic valve replacement group, the adjusted risk for the primary outcome measure was not significantly different across the 4 LVEF groups. This study demonstrates that survival in patients with severe AS is impaired when LVEF is <60%, and these findings have implications for decision making with regard to the timing of surgical intervention. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.