A patient presented with symptoms of gastric outlet obstruction. On evaluation she was found to have a polypoidal lesion in the proximal jejunum on upper gastrointestinal barium series. Endoscopic evaluation showed the gastric mucosa prolapsing into the duodenum. At laparotomy, the gastric mucosa was found to prolapse into the jejunum via the duodenum. Excision of the prolapsed mucosa resulted in resolution of the patient's symptoms.