A 32-year-old woman was referred due to abdominal pain and elevated liver enzymes. Computed tomography and magnetic resonance imaging showed ectopic opening of the common bile duct (CBD) into the duodenal bulb. Esophagogastroduodenoscopy showed a hemispheric bulge in the duodenal bulb. Endoscopic retrograde cholangiopancreatography (ERCP) revealed the bulge to be cystic dilatation of the CBD. ERCP also showed no communication between the ventral and dorsal pancreatic ducts. We diagnosed the patient with ectopic opening of the CBD accompanied by choledochocele and pancreas divisum. Endoscopic incision was performed for the treatment of the choledochocele. The patient's symptoms and elevated liver enzymes improved after treatment.