Introduction: The diaphragm is a musculofibrous structure that separates the thoracic cavity from the abdominal cavity. Although it is a continuous sheet, developmentally it is derived from four different sources: the septum transversum, pleuroperitoneal membranes, lateral and dorsal body wall and the mesentery of oesophagus. Methodology: During routine dissection for undergraduate students in the department of Anatomy, Kasturba Medical College, Manipal a rare variation was encountered in a 65 year old female cadaver. Results: We observed a large defect in the left anterolateral aspect of the diaphragm with associated left pulmonary hypoplasia. The muscular contribution to the diaphragm from the left lateral and dorsal body wall was absent leading to the herniation of abdominal contents into the left thoracic cavity which included the stomach, intestinal loops, left colic flexure and the spleen. Conclusion: Diaphragmatic hernias presenting in adult life are rare and most commonly associated with a history of trauma. Congenital diaphragmatic hernia may remain asymptomatic as in the present case which is extremely rare and could be a chance finding during a routine chest x-ray. Knowledge of this anatomic defect in the diaphragm presenting in adult life would help prevent further complications leading to gastrointestinal or pulmonary distress.