We quantified the graded amounts of aortic atherosclerosis (AA) in patients with aortic stenosis (AS) to better delineate the need for preprocedural risk stratification. Complex AA is strongly related to embolic events, especially during open heart surgery and catheterization. Despite the frequency of these procedures in patients with AS and the increased prevalence of atherosclerosis, current guidelines do not recommend screening for AA. Patients with concomitant transesophageal and transthoracic echocardiograms were retrospectively identified. AS and AA were graded by expert reviewers as mild, moderate, and severe according to established guidelines. Three hundred sixty patients (212 men, mean age 69 +/- 14 years) were identified, 186 (52%) without AS, 82 (23%) with mild AS, 55 (15%) with moderate AS, and 37 (10%) with severe AS. There was a strong graded positive association between AA and AS (p <0.00001). The prevalence of severe AA increased across grades of AS. Of all patients with severe AS, 54% had severe AA. Of patients with severe AS not referred for an embolic event, 57% had severe AA. The odds ratio for severe AA was 4.9 (95% confidence interval 2.3 to 10.3) in patients with severe AS compared with without AS. In conclusion, AS and AA are closely correlated. The majority of patients with severe AS have severe AA, even without previous thromboembolic events. This significant atherosclerotic burden may warrant preprocedural risk assessment with transesophageal echocardiography.