We describe a rare case of a celiomesenteric anomaly with concurrent aneurysm. The patient, a 53-year-old man, had no abdominal pain or discomfort. The presence of a celiac artery aneurysm was suspected on the basis of the results of abdominal computerized tomographic scanning and echo ultrasound scanning performed because of proteinuria. Intra-arterial digital subtraction angiographic results showed the anomaly and aneurysm. Because of the risk of rupture of the aneurysm, the lesion was repaired surgically, with the placement of an interpositional prosthetic graft. We found no previous reports of celiomesenteric anomaly with concurrent aneurysm repaired with prosthetic graft.