Aneurysm of the superior mesenteric artery(SMA) are rare, comprising between 5 and 8% of all visceral aneurysm. Recently visceral artery aneurysms have been detected incidently on routine CT and ultrasound(US) studies. Early diagnosis is critical in minimizing the resultant morbidity and mortality. With the progress in angiography and vascular surgery techniques, the use of surgery in dealing with this condition has become more frequent. A case report of large SMA aneurysm and review of the articles are presented.