A 3-year-old boy with purulent otitis media received a chest radiograph as the part of a routine work up. The patient was normal appearing, in no acute distress. The patient's lung and heart sounds were clear and normal. The patient's abdomen was soft, non-distended, and non-tender. An anterior cardiophrenic mass was incidentally identified on the lateral chest radiograph. A computed tomography scan demonstrated a diaphragmatic hernia with bowel loops in the retrosternal space. An exploratory operation revealed a diaphragmatic defect (4 cm in diameter) on the left side of the falciform ligament, through which transverse colon was protruded. There was no hernia sac, and the defect was closed with interrupted No. 2 silk sutures. The child was discharged on the 8th postoperative day without any complications. During 6 months of follow-up period, recurrence was not noticed.