Background: Hypertrophic pyloric stenosis (HPS) is a common cause of gastrointestinal obstruction in childhood. Case presentation: We report a three month old male child with vomiting and weakness that had been started three days before being referred to the hospital. We used ultrasonography to examine this patient and, while the results from the laboratory tests were normal; abdominal ultrasound examination showed HPS with hiatus hernia and abnormal mesenteric vessels pathway. Conclusion: We concluded that hypertrophic pyloric stenosis with presentation in thorax is a rare condition that can be diagnosed with meticulous ultrasound scanning of diaphragmatic hiatus, pyloric canal and mesenteric vessels pathway.

Keywords: Hypertrophic pyloric stenosis, Hiatus hernia, Infant, Ultrasound, case report