Background: Morgagni hernia (MH) is a rare congenital anomaly of the diaphragm. It is a birth defect characterized by herniation of abdominal organs into the thoracic cavity through a retrosternal diaphragmatic defect which inhibits proper lung formation. Case presentation: We report two cases of MH in a set of premature twins aged 9 days, who presented with respiratory distress at King Abdulaziz Medical City, Jeddah. The diagnosis was confirmed by imaging of chest X-ray and CT scan. Both cases were successfully managed through abdominal approach i.e. laparotomy with surgical treatment of the diaphragmatic deformity. Conclusion: The exact pathogenesis of most cases of congenital diaphragmatic hernia (CDH) remains unknown, however there is an increasing evidence indicating that genetic factors play a pivotal role in formation of CDH. Moreover, its occurrence in a set of twins further supports the genetical theory.