Available data on results of lipid-acting drug trials investigating the prevention or treatment of atherosclerotic cardiovascular disease have conclusively shown that: (a)The beneficial results may not be specific for a given pharmacological group of drugs (i.e., niacin, resins, fibrates, reductase inhibitors).(b)For lipid-acting drugs, the extent of cardiovascular benefit may be related to the extent of the effect on blood lipids.(c)Some drugs may be acting by affecting factors not necessarily related to blood lipid levels (i.e., calcium channel blockers and antioxidants of low-density lipoproteins.(d)The differences in endpoints begin to appear after the second year of intervention.(e)The effects on atherosclerosis can be measured objectively by modern angiographic techniques.(f)Patient's signs and symptoms of disease can be beneficially modified.(g)The long-term safety record of the tested drugs seems adequate.(h)The risk–benefit ratio justifies long-term drug treatment of dyslipidemias in patients not responding to life-style intervention.