Bouveret syndrome is a rare cause of gastric outlet obstruction. It is characterised by the presence of an obstructing gallstone in the pylorus or proximal duodenum, which has travelled to its obstructing position via an acquired fistula. Our case involves a 73-year-old man presenting to the acute surgical take with a 2-day history of right-sided abdominal pain and vomiting. His medical history included perforated cholecystitis treated with antibiotics and percutaneous gall bladder drainage, 1 year earlier. Examination and blood tests were suggestive of gastric outlet obstruction. CT abdomen and pelvis demonstrated a large gallstone obstructing the duodenum, confirming a diagnosis of Bouveret syndrome. The patient improved following gastrolithotomy, and was discharged 2 weeks postoperatively. Fistula formation is a complication of chronic cholecystitis and therefore Bouveret syndrome should be considered in patients with a background of gallstone disease presenting with gastric outlet obstruction.