More and more recent studies demonstrate the pleiotropic effects of fibrates. Except lowering plasma lipid levels they can influence blood coagulation abnormalities and stabilise atherosclerotic lesions--a frequent result of the activation of inflammatory cells within the vascular wall. The anti-inflammatory action of fibrates includes inhibiting the release of many cytokines, such as Tumor Necrosis Factor e (TNF-alpha) by these cells. The aim of this study was to evaluate the effect of fenofibrate on the plasma levels of Plasminogen Activator Inhibitor type 1 (PAI-1) and fibrinogen in patients with combined dyslipidemia. Moreover, we assessed the amount of TNF-alpha released by peripheral blood isolated monocytes before and after therapy. Fourteen patients (8 women and 6 men) with hyperlipidemia IIb were treated with micronized fenofibrate (Lipanthyl 200 m, Fournier) in a daily dose of 200 mg for one month. The control group consisted of 12 individuals matched for age with biochemical confirmation of normolipemia. Plasma PAI-1 and TNF-alpha levels were measured by the ELISA method. Fibrinogen levels were measured according to the commonly used Clauss method. Before treatment the haemostatic compounds and TNF-alpha studied were significantly higher in the group with hyperlipidaemia IIb compared to the control group. One-month therapy with fenofibrate resulted in significant decrease of triglycerides and total cholesterol. After treatment, PAI-1 and fibrinogen levels also decreased significantly: PAI-1 from 101.18 +/- 9.74 ng/mL to 81.22 +/- 6.68 ng/mL, p < 0.01 and fibrinogen from 364.5 +/- 29.6 mg/dL to 294.7 +/- 19.3 mg/dL, p < 0.01. The study also revealed that the level of produced TNF-alpha decreased significantly from 2136.0 +/- 250.8 pg/mL to 1336.8 +/- 132.0 pg/mL, p < 0.05. These results may confirm new pathways of fibrates action.