Background-Preoperative management of patients with aortic stenosis (AS) who need noncardiac surgery (NCS) remains controversial. We sought to determine the impact of AS on the postoperative outcomes after NCS. Methods and Results-Patients undergoing NCS with moderate AS (valve area: 1.0-1.5 cm2) or severe AS (valve area: <1.0 cm2) were identified using the surgical and the echocardiographic databases. Using propensity score analysis, we obtained 4 matched control patients without AS for each patient with AS undergoing NCS. The propensity score matching used the 6 revised cardiac risk index criteria, in addition to age and sex. Primary outcome was a composite of 30-day mortality and postoperative myocardial infarction. We matched 634 patients with AS undergoing NCS to 2536 controls. There were 244 patients with severe AS and 390 patients with moderate AS. Thirty-day mortality was 2.1% for AS patients compared with 1.0% in non-AS controls (P=0.036). Postoperative myocardial infarction was more frequent in patients with AS compared with controls (3.0% versus 1.1%; P=0.001). Combined primary outcome was significantly worse for both moderate and severe AS patients compared with respective controls (4.4% versus 1.7%; P=0.002; and 5.7% versus 2.7%; P=0.02, respectively). High-risk surgery, symptomatic severe AS, coexisting mitral regurgitation, and preexisting coronary disease were significant predictors of primary outcome in patients with AS. Conclusion-Presence of AS adversely affects postoperative outcomes among patients undergoing NCS, evidenced by a higher 30-day mortality and postoperative myocardial infarction after NCS. © 2013 American Heart Association, Inc.