Although it is well established that dietary saturated fatty acid intake is an important risk factor for coronary heart disease, there remains substantial controversy regarding whether these dietary fatty acids should be replaced with either carbohydrates, monounsaturated fatty acids, polyunsaturated fatty acids or a combination of these. This review highlights recent studies evaluating the role of dietary fatty acids in atherosclerosis, with a particular emphasis on their roles in lipoprotein oxidation and other potential proatherogenic processes. Curr Opin Lipidol 9:301–307. © 1998 Lippincott–Raven Publishers