Aortic aneurysms in infants and children are quite rare. The use of umbilical artery catheters in the management of critically ill neonates has been associated with infection and subsequent aneurysm formation. There have been 46 cases reported (including our own); most of the aneurysms have been located in the abdominal aorta and have displayed saccular morphology. Through an analysis of the literature, we identified two factors that had significant correlation with improved survival: diagnosis before surgery and surgical repair (P <.05). This report presents the case of a 23-day-old neonate with an abdominal aortic aneurysm and hypertension. On the basis of our literature review, we offer a management algorithm for this rare but very serious complication of umbilical artery catheterization.