29 patients with primary hypercholesterolemia were treated for 8 weeks each with either bezafibrate (200 mg t.i.d.) or gemfibrozil (600 mg b.i.d.) in a randomized cross-over trial. Compared to placebo bezafibrate was significantly more effective on low density lipoprotein (LDL)-cholesterol (-28% versus -18%) and the LDL/high density lipoprotein (HDL) ratio (-34% versus -24%) by exploratory statistics. There was also a trend for a more marked reduction of bezafibrate on total cholesterol and apoliproprotein B as well as more pronounced increase in HDL-cholesterol and apolipoprotein A-I. The triglyceride reduction tended to be more extensive with gemfibrozil. Complicance to both drugs was good. No side-effects were observed. The results are considered important with respect to the potential of bezafibrate in reducing the risk of cardiovascular disease.