One of the most important reasons of liver destruction in obstructive jaundice is reactive oxygen derived compounds which are formed as a result of demolished liver circulation. In this experimental study, we investigated the effects of L-arginine and L-NAME on liver antioxidant system and lipid peroxidation in rats after ductus choledochus ligation (BDL). For this purpose, fifteen rats were divided randomly into three equal groups. BDL group (n=5): bile duct ligation was performed in rats. L-Arginine group (n=5): Anaesthetized rats were given L-arginine (1 mg/kg) for 7 days after BDL. L-NAME group (n=5): Anaesthetized rats were given L-NAME (2 mg/kg) for 7 days after BDL. Liver tissue was removed in all rats under anesthesia seven days after surgical procedure. Tissue was homogenized and malondialdehyde (MDA) and nitric oxide levels, xanthine oxidase, superoxide dismutase (SOD) and catalase (CAT) levels were studied in the homogenate. Liver tissue MDA level of L-arginine group was significantly lower than control and L-NAME groups. Activity of SOD in L-arginine group was significantly lower than L-NAME and BDL groups. Activitiy of CAT and level of NO in L-arginine group were significantly lower than those of L-NAME group. Liver tissue MDA level of L-NAME group was significantly higher than BDL group. These findings show that L-arginine treatment is effective in prevention of oxidative liver destruction as a result of bile duct obstruction.