A 58-year-old male patient had been suffering for 35 years from recurrent cholangitis, biliary sludge and infection-induced stone formation after open cholecystectomy because of empyema of the gallbladder and severe acute and delayed postoperative complications. The pathophysiological origin of this chronic "sump syndrome" was a choledochoduodenostomy which had been performed prophylactically at the time of the initial operation. The patient agreed to an experimental treatment option with use of an Amplatzer atrial-septal defect (ASD) occluder for closure of the symptomatic choledochoduodenal fistula. The double-disc occluder was introduced through a 9 French diameter and 90 cm long sheath side to side with a duodenoscope. Under endoscopic and fluoroscopic guidance the distal disc was opened in the common bile duct, then retracted against the fistula's orifice. Subsequently, the proximal disc was unfolded in the duodenum, while the 9 mm waist between the two discs filled and shut the fistula. No side effects or complications were detected. The day after the procedure, endoscopic evaluation demonstrated the correct position of the occluder and closure of the fistula. Over a period of 12 months, repeated assessments did not reveal any major problems. The patient felt a significant subjective improvement. The use of a self-expanding occluder system for closure of a choledochoduoenotomy complicated by chronic and symptomatic duodenocholedochal reflux might therefore represent an enrichment of the equipment of interventional endoscopists.