Two common coding sequence mutations of lipoprotein lipase (serine447-ter, producing a carboxy terminal truncation; and asp9-asn variants) were studied in 329 Caucasian subjects, of whom 243 had angiographic features of premature atheroscelerosis (220 with coronary artery disease; 23 with coronary and peripheral artery disease). As expected, the mean levels of cholesterol, triglycerides, LDL-cholesterol, ApoB and Lp(a) were significantly higher in the arterial disease group than in the controls. HDL levels were lower in the patient group. With regard to the common mutations, plasma triglycerides and VLDL-triglycerides were lower in subjects possessing the Serine447-Ter mutation (p = 0.06 and < 0.05, respectively). When the lipid distributions were analysed by tertiles, the Ser447-Ter mutation was significantly less frequent in the highest tertiles for triglycerides (p < 0.02), and VLDL (p < 0.04). The Asp9-Asn substitution was significantly more frequent in the lowest tertiles for ApoAI (p = 0.05). Case-control analyses of genotypic distributions between the two groups with or without arterial disease did not show any significant differences. The possible functional effects of these common mutants of lipoprotein lipase are discussed.