Despite intense debate on the benefits of cholesterol lowering, the use of lipid-lowering drugs has risen substantially in most countries. This change in attitude has accompanied the appreciation of data from initial observational studies on large cohorts that established the link between elevated serum cholesterol and coronary heart disease and randomized controlled trials of cholesterol lowering that demonstrated improvements in coronary morbidity and mortality seen in patients with or without coronary heart disease. Data are now accumulating on the effects of lowering serum triglyceride levels in improving coronary risk. More studies are still required, but metabolic studies indicate that high serum triglycerides are a marker for the presence of atherogenic small dense low-density lipoproteins. Low concentrations of high-density lipoprotein cholesterol is also a marker for coronary risk, but the case for increasing levels by drugs is unclear. The rationale for the use of lipid-lowering drugs becomes more evident with an understanding of the mechanisms that cause hyperlipidaemia. In addition to serum lipid values, a good clinical history and examination are an essential part of assessing coronary risk. Certain groups, such as women, children, elderly people and patients with genetic hyperlipidaemias or liver or renal disease, need a special approach to therapy. The better tolerability and widespread use of the newer lipid-lowering drugs have raised issues of cost effectiveness. New lipid-lowering drugs are being developed, and there is some evidence that existing lipid-lowering drugs may produce benefit beyond that related to lipid lowering.