Congenital diaphragmatic hernia (CDH) is associated with displacement of abdominal organs in to the thoracic cavity and the most serious form of these defects is the complete absence of hemidiaphragm.Classification of CDH as diaphragmatic agenesis (DA) or classical CDH is based on findings at operation. With DA there is a very large diaphragmatic defect requiring a prosthetic patch or muscle flap for closure (1) . Owing a worse prognosis in diaphragmatic agenesis intensive preoperative preparation and postoperative ventilatory care are required when compared to classical CDH (1).C Ca as se e R Re ep po or rt t A female full-term neonate weighing 3500 g was born by vaginal delivery to a 34 year old mother. Prenatally, ultrasound examinations failed to show any abnormalities. On delivery, she was intubated, ventilated, and an umblical catheter was placed. A chest x-ray showed a left-sided CDH. Pre-operative echocardiogram revealed persistence of left superior vena cava, which was the only associated cardiovascular abnormality. Radial artery blood gas analysis was made on admission and again when stabilized preoperatively. She underwent surgery within the first 12 hours of life. A laparotomy was performed