There were five clinical centers and a coordinating center in the pilot study. There were four pre-randomization visits at four to six week intervals. Subjects were eligible for inclusion if their LDL cholesterol levels remained above 120 mg/dl after the introduction of the American Heart Association Step 1 Diet at Visit 2. Subjects were randomized to diet plus a low dosage of lovastatin (20 mg), diet plus a high dosage of lovastatin (40 mg), or to diet plus a placebo. End points were changes in blood lipid levels. Data on other blood chemistry values, as well as quality-of-life measures and coronary heart disease morbidity and mortality, were also collected. LDL cholesterol levels were measured at clinic visits six and twelve weeks after randomization and at twelve week intervals thereafter. Serum alanine aminotransferase levels were measured at six week intervals to determine liver function and slit lamp exams were performed before and after study medication to detect lenticular opacities. Subjects were followed for a minimum of six months and a maximum of fifteen months.