The aim of this study was to investigate the relationship between plasma viscosity and lipoprotein and apolipoprotein pattern in normo- and hypercholesterolemic patients with peripheral occlusive arterial disease (POAD). 40 patients with POAD have been selected (8 females and 32 males, mean age: 54 +/- 3.2 years) with clinically evident superficial femoral occlusive artery disease. They were separated into two groups as normocholesterolemic (plasma total cholesterol <200 mg/dl) and hypercholesterolemic (plasma total cholesterol >200 mg/dl). Plasma total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides, total protein, and albumin levels were determined by enzymatic methods using commercial kits. Levels of apolipoprotein AI (apo AI), and apolipoprotein B (apo B) were measured using a immunoturbidometric method. Plasma viscosity (PV) was measured by capillary viscometer. Classifying the patients with PAOD according to the cholesterol levels; hypercholesterolemic (mean total-cholesterol: 227.90 +/- 26.97 mg/dl) patients had significantly higher LDL-C, PV and triglyceride levels compared with nornocholesterolemic patients (p < 0.001, p < 0.001, p < 0.001, respectively). HDL-C and apo B were significantly lower in hypercholesterolemic patients than in normocholesterolemic patients (p < 0.001, p < 0.001, respectively). PV was positively correlated with total cholesterol (r = 0.485, p < 0.05), atherogenic index (r = 0.624, p < 0.01), total-C/HDL-C ratio (r = 0.624, p < 0.05), and LDL-C/HDL-C ratio (r = 0.707, p < 0.001) in hypercholesterolemic patients with POAD. PV was higher in hypercholesterolemic patients with POAD than in normocholesterolemic patients with POAD.