A 16-year-old boy was admitted with an 8-year history of abdominal pain, vomiting, and growth retardation. There was no history of peptic ulcer or caustic ingestion. He was severely cachexic, and barium meal showed a dilated stomach with delayed gastric emptying time and no contrast in the duodenum afterward. Exploratory laparotomy demonstrated a grossly dilated stomach with a smooth wall and a stenotic ring at the pylorus but without any muscular hypertrophy. There was no extrinsic compression of the pylorus or any scarring near it. Heineke-Mikulicz' pyloroplasty was performed. Histopathological examination of the pylorus showed normal cellular pattern without any neoplastic or inflammatory cells. The patient improved postoperatively and gained 8 kg in the first month following the operation.