Aging is a major risk factor in the development of cardiovascular diseases attributed to the development of vascular endothelial dysfunction. Reduced bioavailability of endothelial- nitric oxide (NO) synthase (eNOS) and its product NO is considered the key mechanism mediating reduced endothelial function with aging. Vascular oxidative stress and inflammation increase with age and Western diets rich in fat, specifically saturated fat, refined carbohydrates and limited plant foods increase oxidative stress and inflammation. In aged endothelium, Western diets can augment endothelial dysfunction because functional changes have already likely begun. This review discusses possible mechanisms responsible for endothelial dysfunction in aging and the links between endothelial aging and Western diets.