Background: Many symptomatic patients with severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF) are denied surgery and have a grim prognosis with medical management. Methods and Results: Between 2003 and 2012, among 550 patients with severe isolated AS and preserved LVEF on transthoracic echocardiography, 241 did not undergo aortic valve replacement (mean age, 83.2±7.6 years; 54% female; aortic valve area index, 0.40±0.13cm²/m²; mean LVEF, 64.8±7.6%) and 67% presented with cardiac symptoms. At a mean follow-up of 25.5±25.1 months, 134 patients (56%) had died. Survival at 1, 5 and 9.5 years was 71%, 28% at 12%, respectively. Median survival was 36.3 months (95% confidence interval [CI]: 27.2–42.4 months). In unadjusted analyses, age, heart failure, hypertension, renal insufficiency, left atrial size, pulmonary artery systolic pressure (PASP), relative wall thickness and LV mass/LV end diastolic volume ratio were associated with mortality. On multivariate analysis adjusted for all significant univariate predictors, age ≥78 years, history of hypertension, left atrial diameter ≥40mm and PASP ≥42mmHg gave a joint area under the curve of 0.80 (95% CI: 0.73–0.86) for mortality. Conclusions: In medically treated patients with severe isolated AS and preserved LVEF, older age, history of hypertension, and echo-Doppler variables reflecting LV diastolic dysfunction are independent predictors of death.  (Circ J 2014; 78: 232–239)