A 51-year-old woman with autoimmune pancreatitis is reported in whom treatment with ursodeoxycholic acid (UDCA) was beneficial. Complaining of epigastric discomfort, she presented with liver dysfunction of the cholestatic type, and diabetes mellitus. Pancreatic imaging revealed a diffuse swelling of the body, an irregular narrowing of the main pancreatic duct, and a terminal stricture of the common bile duct. Histologically, the biopsied pancreas was replaced by fibrous tissue with a small amount of mononuclear cell infiltration. She had anti-carbonic anhydrase-II antibody and anti-lactoferrin antibody. After treatment with UDCA, her liver dysfunction and diabetes mellitus improved and the pancreas size was reduced. Steroid therapy is usually indicated for this disorder, but UDCA may be given as an alternative choice.