The classical lipoproteins have been extensively studied for their effects on the development of coronary artery disease and atherosclerosis in general. Although low-density and high-density lipoproteins are emphasized in determining risk and in devising treatment strategies, other less common lipoprotein classes have been identified that promote atherogenesis, predominantly by bypassing normal metabolic pathways that serve to limit vascular intracellular lipid deposition. This review discusses three such classes, which represent variants of the classical lipoprotein fractions: remnant lipoproteins, which are degraded chylomicron and very low-density lipoprotein particles; and two fractions that are associated with a low-density lipoprotein type core, oxidized LDL and lipoprotein(a). Current understanding of the metabolism of these atherogenic lipoproteins, of the factors that affect synthesis and degradation, and of their response to dietary and nutritional factors is still limited.