Cholestasis-induced liver injury during bile duct obstruction causes an inflammatory response and this inflammatory process may be an important source of tissue injury. We hypothesized that NF-kappa B inhibition would decrease liver injury in a rat model of extrahepatic biliary obstruction. A total of 40 female rats of Sprague-Dawley strain were allocated to four groups. First group was sham operated control. The second group underwent common bile duct ligation (BDL) and was monitored for 10 days. Third group of rats underwent BDL and received pyrrolidine dithiocarbomate (PDTC) at a dose of 100 mg/kg/day intraperitoneally. Fourth group underwent BDL and received sulfasalazine at a dose of 100 mg/kg b.w. Both inhibitors were administered once a day throughout last 7 days of the experimental period. Rats were terminated 10 days after sham operation or BDL. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamil transpeptidase, and tumor necrosis factor-alpha levels were elevated in the BDL group as compared to the control group, while this increase was significantly decreased by treatment with PDTC and sulfasalazine (P < 0.05). Hepatic GSH, SOD and catalase levels were significantly depressed by BDL, but were elevated back to control levels in NF-kappa B inhibitor-treated BDL groups. Increases in tissue free radical and MDA levels and MPO activity due to BDL were reduced back to control levels by NF-kappa B inhibitor treatment (P < 0.05). Similarly histological damage in the BDL rats was reduced by treatments. These results indicate that inhibitors of NF-kappa B activity such as PDTB and sulfasalazine exert a therapeutic effect on cholestatic liver injury in rats with BDL through anti-inflammatory and antioxidant actions.