Higher plasma triglyceride levels and decreased HDL-cholesterol concentrations are usually accompanied by the presence of small, dense LDL in the so-called lipid triad or 'atherogenic lipoprotein phenotype'. This phenotype is highly atherogenic and its prevalence may suggest an even higher overall burden of atherosclerotic disease as compared with that associated with hypercholesterolemia. As stated by the National Cholesterol Education Program Adult Treatment Panel III, there is evidence suggesting each component of this lipid triad is individually atherogenic. However, the relative contribution of each component cannot be easily determined. Therefore, it has been suggested to consider the atherogenic lipoprotein phenotype as a whole as a risk factor. This is supported by data from epidemiological studies considering high-risk populations, which showed that the contribution to cardiovascular risk of each individual component cannot be dissected from the sum of all factors. We recently investigated the prevalence of the atherogenic lipoprotein phenotype in different categories of patients at higher cardiovascular risk: with coronary and noncoronary forms of atherosclerosis or metabolic diseases, including Type 2 diabetes, polycystic ovary syndrome and growth hormone deficiency. Subjects with higher triglyceride levels, decreased HDL-cholesterol concentrations and increased levels of small, dense LDL (i.e., subjects with the atherogenic lipoprotein phenotype) are common in coronary and noncoronary forms of atherosclerosis. In the future, it may be possible to measure the presence of small, dense LDL to identify subgroups at higher cardiovascular risk.