Spontaneous internal biliary fistulas are not an uncommon complication of primary biliary disease. Almost 90% of the abnormal biliary-enteric communications between the gallbladder and the duodenum are caused by perforation via gallstones into an otherwise normal duodenum. However, biliary-enteric communications that are caused by primary duodenal ulcer disease are much less common. We experienced a case of duodenal peptic ulcer disease that perforated into the common bile duct in a 45-year-old woman.