BACKGROUND/AIMS: Autoimmune cholangitis (AC) is a disease with clinicopathologic features of pri mary biliary cirrhosis (PBC) without antimitochondrial antibody (AMA). The aim of this study was to compare the clinicopathologic features and the biochemical response to ursodeoxycholic acid (UDCA) in patients with autoimmune cholangitis (AC) and primary biliary cirrhosis (PBC). METHODS: We retrospectively reviewed the clinical, histological and biochemical features of 8 patients with AC and compared them with those of 10 patients with PBC. Seven patients in each group were given UDCA (600 mg/day) and followed monthly for more than 12 months. RESULTS: All patients of both groups were female. ANA were detected in 100% of patients with AC and in 60% of patients with PBC (p=0.09). IgG and IgM levels were significantly higher in the patients with PBC than in the patients with AC (p=0.02 and p=0.04, respectively). In both groups, the mean levels of alkaline phosphatase and gamma glutamyl transferase at 12th month after treatment with UDCA decreased significantly (p=0.018 and p=0.02 in AC, p=0.04 and p=0.04 in PBC, respectively). CONCLUSIONS: Although the presence of autoantibodies and the levels of immunoglobulin are distinguishing labora tory features, the clinical features and the response to UDCA are similar in AC and PBC. It isuggested that AC seems to be AMA negative PBC and AC and PBC could be treated similarly.