The aim of the study was to evaluate the direct influence of lipid parameters (total and HDL-cholesterol, triglycerides and total lipids) on the rheologic-coagulative pattern. We studied blood rheological properties--blood (BV), plasmatic (PV), and seric (SV) viscosity, whole blood (WBF) and red cell (RCF) filterability--and some coagulative factors--fibrinogen (Fib), levels of clotting factor VII (fVIIc) and VIII (fVIIIc) activity--in 156 men aged 40-54 years; 87 patients had type II hyperlipoproteinemia (46 type IIa and 41 type IIb) and 69 were normolipemic controls. Smokers, patients with arterial hypertension, diabetes mellitus or cardiovascular clinical manifestations were excluded. Type IIb hyperlipoproteinemic patients had increased blood viscosity (shear rate 225 sec-1, p. less than 0.01), which was positively correlated with triglycerides and fibrinogen concentration. Levels of fibrinogen, fVIIc and fVIIIc activity did not differ significantly in hyperlipemic patients and controls, although fVIIc activity and fibrinogen were both positively related with lipid parameters. These data suggest that, in absence of other major risk factors, the alterations of the rheologic-coagulative pattern are mainly dependent on the severity of the lipid disorder.