Congenital or traumatic hernia complicating pregnancy is a rarity but death occurs in half of the cases. Complications (respiratory distress, intestinal obstruction) are more frequent during the third trimester, during delivery and in the post-partum hours. In the asymptomatic patient, surgery should be performed specially in the first and second trimesters. During the third trimester, fetal maturity should be watched and the defect should be repaired at the time of elective cesarean section. Active labor should be avoided because of the increased abdominal pressure produced during the expulsion period. If an unexpected labor occurs, forceps application, if cesarean section could not be performed, should be realised. If signs of respiratory distress or of obstruction arise at any time, immediate repair should be undertaken, regardless of the age of pregnancy. An hernia operated before the pregnancy could recur during this one (this is the case of the author). Il is possible that some diaphragmatic hernias no complicated during previous pregnancies could be aggravated without symptoms and are complicated during a further pregnancy.