We determined whether the normalization of serum bilirubin level (SBL) induced by ursodeoxycholic acid (UDCA) therapy was associated with an improved clinical outcome in patients with primary biliary cirrhosis (PBC). We estimated the prognostic values of SBL measured after 6 months of UDCA treatment for survival free of orthotopic liver transplantation (OLT). We used a database of 548 patients with PBC followed in three trials of UDCA. Among UDCA-treated patients, we compared survival free of OLT in patients with normalized SBL (