Diaphragmatic hernia in the absence of trauma in adults is very rare. It occurs as a result of unilateral diaphragmatic agenesis. The diagnosis of this rare condition is typically made in early infancy. However, in asymptomatic patients, the diagnosis is often delayed for months and even years. We present a case of a 27-year-old female, who was referred 48-hours after Caesarean section with suspected pulmonary embolism. Computed tomography scan revealed herniation of the liver as well as bowel loops into the right hemi-thorax. Exploration through a right thoracotomy revealed right diaphragmatic agenesis. The contents were reduced into the abdomen, and the defect was repaired using a mesh. The patient had an uneventful postoperative recovery and was discharged home 10 days later. This case highlights the acute late presentation of right diaphragmatic eventration with abdominal visceral herniation in adulthood. The condition may be triggered by the increasing size of gravid uterus.