Gastric duplication malformation, also known as double stomach, is extremely rare clinically and accounts for approximately 9% of all GI malformations. The incidence of this disease has been reported in isolated cases and the incidence in the population is unknown. According to available data, the disease is more common in children and adolescents, with slightly more females than males. Symptoms examined are poor appetite, epigastric discomfort, dull pain, anemia, weight loss and malnutrition. If there is a duct of ectopic pancreas connected to both stomachs, it shows recurrent pancreatitis. If ulcers occur in both stomachs, blood may enter the intestine through the duct of ectopic pancreas and symptoms of black stool or upper gastrointestinal bleeding may appear. The abdominal examination usually reveals a cystic mass in the upper abdomen, which is superficial and may move. Once the diagnosis of bigastric is clear, prompt surgical treatment is indicated. The usual method is to remove both stomachs together with the shared gastric wall and then perform a gastric wall anastomosis, which is a practical and reliable method with few complications. In addition, partial gastrectomy can be performed. In cases of combined ectopic pancreas, double stomach with ectopic pancreatic ducts or even with normal pancreatic ducts, the ectopic pancreas should be removed and its passage should be cut off outside the near normal pancreas in order to prevent recurrence of pancreatitis.