Purpose: many studies in experimental models have evidenced the presence of inflammation in venous vascular dysfunction and the implication of TNF-α in vascular pathology, through its prooxidant and proinflammatory effect. Starting from these studies, we experimentally investigated the effect of treatment with a TNF-α inhibitor, etanercept, on the oxidant/antioxidant balance in rats, with the partial obstruction of the common femoral vein. Methods: the researches were carried out in 7 groups of animals (n=10 rats/group), 6 groups undergoing surgery and a control group. In 3 groups, the ligation of the common femoral vein was performed (groups 1, 2, 3), 3 groups underwent the ligation of the common femoral vein and received etanercept (groups 4, 5, 6), in a dose of 1 mg/kg, one dose per week, according to data found in literature. The serum indicators of the O/AO balance were determined: indicators for oxidative stress (malondialdehyde (MDA), protein carbonyls (PC)), indicators for non-enzymatic AO defense (thiol groups (SH), hydrogen donors (HD ), glutathione (GSH)) at weeks 1, 2 and three. Results and Conclusions: chronic venous insufficiency with and without anti-TNF-α treatment induced changes in the oxidant/antioxidant balance compared to the control group; after the administration of the anti-TNF-α preparation, oxidative stress was maintained on account of MDA that increased significantly, and decreased significantly on account of PC compared to the untreated groups; after the administration of the anti-TNF-α preparation, at two and three weeks there was an insignificant increase in antioxidant defense on account of HD and GSH compared to the untreated groups; the administered anti-TNF-α preparation had late and insignificant effects in chronic venous insufficiency.