The balance among cholesterol synthesis, dietary intake, and degradation is normally adequate to maintain healthy cholesterol plasma levels. However, in patients with hypercholesterolemia, elevated low-density lipoprotein cholesterol leads to atherosclerotic deposition of cholesterol in the arterial walls. Consequently, in this population it has been established that lowering low-density lipoprotein cholesterol plasma concentrations effectively reduces cardiovascular morbidity and mortality. The National Cholesterol Education Program Adult Treatment Panel III has therefore identified control of low-density lipoprotein cholesterol as essential in the prevention and management of CHD. Additional lipid risk factors designated by National Cholesterol Education Program Adult Treatment Panel III include elevated triglycerides, elevated non-high-density lipoprotein cholesterol (atherogenic lipoproteins), and low levels of high-density lipoprotein cholesterol. Lipoproteins rich in triglycerides, such as very-low-density lipoprotein cholesterol, appear to contribute to atherosclerosis, whereas the apparent protective effect of high-density lipoprotein cholesterol, which is likely related to high-density lipoprotein cholesterol-facilitated transport of cholesterol away from atherosclerotic deposits, may be limited at low high-density lipoprotein cholesterol concentrations.