BACKGROUND A cholecystoenteric fistula (CEF) is a rare complication of gall stone disease. While a cholecystoduodenal fistula is the most commonly occurring bilioenteric fistulous communication, cholecystocolonic, cholecystogastric and choledochoduodenal fistulas have also been described. CASE REPORT A 73-year-old woman presented with a 1-week history of melena on a background of acid reflux and no abdominal pain. A gastroscopy revealed kissing D1 ulcers with excretion of pus. Following a CT scan of the abdomen, the patient was referred to the surgical team for the management of acute cholecystitis with a cholecystoduodenal fistula. She underwent an open cholecystectomy with fistula take-down and repair of the duodenum in the same admission. Following an uneventful postoperative recovery, she was discharged on an empirical course of H. pylori eradication therapy. Recurrent episodes of acute cholecystitis or chronic cholecystitis can lead to adhesions between the gall bladder and adjacent viscus. Gall stone impaction then can cause pressure necrosis, leading to a fistulation between the gall bladder and the viscus. Rarely, this presents with massive upper-gastrointestinal bleeding. Imaging with ultrasound can reliably diagnose cholelithiasis, cholecystitis, and pneumobilia, but is unlikely to help in the definitive diagnosis of a bilioenteric fistula, which requires cross-sectional imaging. CONCLUSIONS Massive upper-gastrointestinal bleeding is a rare mode of presentation of CEF. Hemodynamic resuscitation and management of upper-GI bleed takes precedence, followed by definitive management of the CEF after establishment of the diagnosis.