The immunosuppressive agent cyclosporine A (CsA) has been reported to exert measurable hepatotoxic effects. One of the causes leading to hepatotoxicity is thought to be reactive oxygen radical formation. Therefore, this study was designed to elucidate possible relation between cyclosporine A treatment and antioxidant capacity (AOC) of hepatic tissue and, to determine if antioxidant supplementation is beneficial. Cyclosporine A was given to 20 rabbits orally for 10 days. Vitamins E and C combination were given intramuscularly. Vitamin therapy was started 3 days before cyclosporine A treatment and continued for 10 days. In each group (control, cyclosporine A, cyclosporine A+vitamin, and vitamin only) there were five animals. After the animals were sacrificed, their livers were removed to be used in the AOC measurement. AOC was found to be lower in cyclosporine A group compared to control and vitamin groups. Results suggest that reduced antioxidant capacity may play part in the cyclosporine A-induced hepatotoxicity and use of some antioxidants may give beneficial results.