Growing evidence suggests that dietary factors play an important role in modulating endothelial function. Epidemiologic and clinical studies have related intake of alpha-linolenic acid and long-chain n-3 fatty acids to lower plasma concentrations of inflammatory cytokines and endothelial adhesion molecules, both of which are considered markers of endothelial dysfunction. In contrast, trans fatty acid intake and a higher dietary glycemic load have been associated with increased plasma concentrations of these biomarkers. Recently, several epidemiologic and intervention studies have examined the relationship between overall dietary patterns and endothelial dysfunction. In general, a "prudent diet," characterized by higher intake of fruits, vegetables, legumes, fish, poultry, and whole grains, is associated with a beneficial effect on the endothelium. Conversely, a "Western diet," characterized by higher intake of red and processed meats, sweets, desserts, French fries, and refined grains, is associated with an impairment of the endothelial function. These findings provide additional biological mechanisms through which dietary factors influence the risk of cardiovascular diseases.