BACKGROUND It is thought that immunosuppressive treatment, besides anti-rejection properties, leads to pathological changes within the organ due to activation of mechanisms associated with oxidative stress. The aim of this study was to examine the parameters of oxidative stress in the livers of rats treated with the most commonly used transplant recipient drug regimens. MATERIAL AND METHODS The rat livers were obtained from archival material obtained from the previously performed experiment. Malondialdehyde (MDA), reduced glutathione (GSH) concentrations, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were analyzed. RESULTS Only the group treated with tacrolimus (T), mycophenolate mofetil (M), and prednisone (P), the TMP group, showed a slight increase in lipid peroxide concentration compared to the control group, though the difference was not statistically significant. Comparison of lipid peroxide concentration between the other treatment combinations and the control group showed a significant decrease. Additionally, a difference in lipid peroxide concentrations in the livers was observed between the cyclosporine A (C) group and tacrolimus (T) group. Alterations of other oxidative stress parameters were also observed in different regimens. CONCLUSIONS Long-lasting immunosuppressive treatment does indeed affect redox status; however, the antioxidant defenses of the liver against the effects of excess hydrogen peroxide are efficient, so the superoxide dismutase/glutathione peroxidase (SOD/GPx) and superoxide dismutase/catalase (SOD/CAT) ratios were not significant.