Overnight fasting plasma lipoprotein and lipid concentrations were measured in a group of 76 patients with peripheral arterial disease (PAD)--main symptom: intermittent claudication--and compared to those of 21 controls, matched with the patients according to age, sex, body-mass index, alcohol and tobacco consumption, but without any signs of peripheral arterial disease. Significantly lower median values of high density lipoprotein cholesterols (HDL-C) (P less than 0.01), and significantly higher median values of low density lipoprotein cholesterols (LDL-C) (P less than 0.05) were found in the PAD group. The results also showed significantly lower ratios of HDL-C/LDL-C and HDL-C/total cholesterol in the PAD group when compared to the controls (both P less than 0.005). No significant differences were demonstrated concerning very low density lipoprotein, total cholesterol, or triglyceride plasma concentrations. Evaluation of arteriograms showed a significant negative correlation between HDL-C concentrations and the extent of arteriosclerotic lesions in the lower extremities (P less than 0.05). Thus, not only were the HDL-C and LDL-C levels different in the PAD group, but we also found a correlation between HDL-C and the severity of vascular disease.