Introduction: Larrey’s cleft hernia is defined by the permanent or intermittent passage of part of the abdominal contents through the costo-xyphoid hiatus of the diaphragm. Its occurrence in trisomy 21 is classic, but its association with diaphragmatic eventration is rare. We report the case of a 03-year-old patient with Down syndrome who presented an anterior diaphragmatic hernia associated with diaphragmatic eventration. Observation: A.H, aged 03 with Down syndrome, was admitted to the Thoracic Surgery Department of Fann Hospital for the management of a hernia of the Larrey’s cleft. On admission, she presented a sub occlusive syndrome, without vomiting or rectal bleeding, the abdomen was supple, depressible, with no palpable mass. Thoracic-abdominal-pelvic computed tomography showed a midline anterior diaphragmatic hernia (Larrey). The barium enema showed an uninhabited right iliac fossa with intra thoracic digestive gas in front of the heart, an attachment anomaly affecting the cecum, with sigmoid dollish-colon. Larrey's hernia was repaired by supra umbilical midline laparotomy. After 3 weeks, the child again presented an occlusive syndrome, and the CT scan was strongly suggestive of a recurrence of the hernia. Revision by right thoracotomy supplemented by a mini subcostal approach made it possible to rectify the diagnosis, highlighting diaphragmatic eventration, which was treated by plication. The suites were simple. Conclusion: The association of diaphragmatic eventration and hernia of Morgagni is possible and surgical treatment gives good results.