Although a number of publications have described the natural history of patients with aortic stenosis (AS), the definition of “natural history” varies widely. Those describing a large number of patients with AS without operative therapy with necropsy findings are rare. Two hundred sixty patients >15 years of age with AS were studied at necropsy over a 50-year period by the same investigator. Of the 260 patients, the valve in 37 (14%) was congenitally unicuspid, in 123 (47%), congenitally bicuspid, and in 100 (38%), tricuspid. Aortic valve structure varied with age of death (in years; unicuspid 52 ± 17, bicuspid 63 ± 12, and tricuspid 70 ± 14 years); gender (men/women: unicuspid 95%/5%, bicuspid 78%/22%, and tricuspid 63%/37%), and frequency of calcium in the mitral valve annulus and epicardial coronary arteries. The patients with cardiac-related symptoms compared with those without were more likely to have a congenitally malformed valve (unicuspid 17% vs 12%; bicuspid 51% vs 29%; tricuspid 31% vs 60%; unadjusted p = 0.013), to die from cardiac disease (86% vs 54%; unadjusted p = 0.001), and to have larger hearts (mean cardiac weight 606 ± 138 g vs 523 ± 121 g; unadjusted p = 0.009) and a larger quantity of calcium in the aortic valve cusps. In conclusion, the length of survival in adults with AS is related to valve structure, gender, presence of cardiac-related symptoms, cardiac mass, and quantity of calcium in the aortic valve cusps.