Vomiting is a common symptom of a multitude of diseases in children. It is usually part of benign illness and can occur at any age. Recurrent vomiting can be a symptom of life-threatening medical or surgical emergencies. It can be rarely caused by an extraluminal pyloric duplication cyst. Early recognition is essential for preventing delays in management and potential complications. Here we report a case of an extraluminal pyloric duplication presenting as progressive gastric outlet obstruction cyst in a 14-month-old Syrian boy. The diagnosis was made through abdominal ultrasound, gastrointestinal endoscopy and abdominal computed tomography scan.