A case of abdominal aortic aneurysm associated with renovascular hypertension in a 3-year-old boy is reported. The child was treated by resection of the aneurysm and replacement with a 12 mm polyester (Dacron) bifurcated graft. The cause of the aneurysm was not revealed by clinical and pathologic examination. In addition to the case report, the Japanese-language literature is reviewed. The most frequently reported etiologic factor was Kawasaki disease; we could not find any evidence of connective-tissue disorder as a cause for abdominal aortic aneurysms occurring in children.