In a controlled clinical trial with a placebo prephase, the comparison of the two lipid-lowering drugs etofibrate and gemfibrozil showed no clinically relevant differences of lipoprotein profile modification in 50 patients with combined hyperlipidaemia. Under both treatments, there was a marked and significant reduction of triglycerides associated with a significant decrease of total cholesterol. In both treatment groups, the percent increase of high density lipoprotein HDL cholesterol was significantly correlated to the pretreatment levels of HDL cholesterol. Tolerance was better under etofibrate with no reported side effects compared to gemfibrozil with two reported cases of gastrointestinal side effects.