We report the case of a 74-year-old man with a colovesical fistula caused by a gallstone that was lost during a laparoscopic cholecystectomy 7 months earlier. The patient was cured after undergoing colonoscopic removal of the stone. To our knowledge this is the first case report of such a complication in the English literature. The report reviews the outcome and complications of retained intraperitoneal gallstones.