Bochdalek hernia is thought to be the result of a defect of the pleuroperitoneal fold and the septum transversum fusion in the 8th week of gestation. The majority of these patients present with respiratory distress after delivery; asymptomatic progress until adulthood is an extremely rare clinical occurrence. The adult form of a Bochdalek hernia accompanying pregnancy is a rare entity. A 39-year-old, 24-week pregnant patient applied to Emergency service with epigastric pain and vomiting. Abdominal ultrasonography was planned due to the abdominal pain; sudden cardiopulmonary arrest occurred during the procedure. In this case report, congenital diaphragmatic hernia in a young pregnant woman who underwent cardiac arrest is presented.