Several antihypertensive agents have been found to influence serum lipid profiles. Thiazide diuretics increase total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels and slightly reduce high-density lipoprotein (HDL) cholesterol. Most beta-blockers substantially increase triglycerides and lower HDL cholesterol. Angiotensin-converting enzyme inhibitors, calcium channel antagonists, alpha- and beta-blockers, and beta-blockers with intrinsic sympathomimetic activity are lipid neutral. alpha 1-Antagonists (e.g., terazosin and prazosin) lower total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels and improve total cholesterol/HDL ratios. Observational epidemiologic studies indicate that the lipid effects of antihypertensive agents are large enough to account for substantial differences in the predicted incidence of coronary heart disease. Combination therapy with the alpha 1-antagonist terazosin plus either thiazides or beta-blockers also ameliorates the adverse lipid effects of these agents used alone. A reasonable approach to managing the lipid problems often associated with hypertension is to advise a cholesterol-lowering, low-sodium diet and weight reduction and to select drugs that alone or in combination do not adversely affect lipid profiles.