An 83 year old caucasian gentleman presented with vomiting and left sided abdominal pain. A subsequent upper GI endoscopy demonstrated a large smooth mass impacted within the duodenum. A cholecysto-duodenal fistula was discovered at laparotomy, with a large gallstone impacted in the duodenum. A diagnosis of Bouveret's syndrome was made. The management of this rare cause of gastric outlet obstruction is discussed.