Intoduction: Morgagni hernia is a herniation through the costosternal portion of diaphragm. Morgagni's defect usually occurs on the right side. Morgagni hernia is a rare hernia and occurs more commonly in adults.

Case report: A 4 years old child was referred to office for recurrent pneumonias. The patient was under treatment for his pneumonias since 2 years ago. On chest CT scan, transverse colonic segment and air fluid level was seen in the right hemi thorax.

Conclusion: With the diagnosis of Morgagni hernia, the patient was prepared for operation. Surgical approach was right thoracotomy. Herniated colon through morgagni defect was observed. The hernial sac was set free from a 2.5x2.5 cm defect in the anterior part of diaphragm. The colon was moved in to abdomen. The defect was repaired by 1-0 nylon sutures. After operation and often 1.5 years follow up, the patient is well with no complications.