Hyperlipidemia and the atherosclerotic conditions that result from it are well recognized as major contributors to coronary heart disease (CHD). Fortunately, several large-scale clinical trials have shown that there are effective treatments that can substantially lower atherogenic lipid levels and thereby reduce the risk of CHD mortality and morbidity. However, duplication of these dramatic trial results can be negatively affected in "real life" clinical practice by an important issue: compliance. No medications will work if patients do not take them. Unfortunately, patients who need lipid-lowering therapy are likely to need it long-term, perhaps for a lifetime. Yet, many do not adhere to the prescribed medication regimen. This article reviews some major studies of compliance for lipid-lowering drugs. The reasons why patients do not take them as prescribed vary: poor education, lack of understanding, cost, provider indifference, and others. Achieving compliance requires a multifaceted approach. It can be enhanced by encouraging patients to talk openly about their medication habits and by convincing them of the long-term benefits of reaching and maintaining target low-density lipoprotein cholesterol levels. Although more studies focusing on compliance specifically regarding CHD are needed, the current literature does provide some guidance. Arch Fam Med. 2000;9:1169-1175