Congenital (primary) neonatal abdominal aortic aneurysm (AAA) is an extremely rare truncular arterial abnormality among numerous congenital vascular malformations. Only seven cases have been reported as congenital origin in newborns. This report presents the case of a male infant in whom a 33-mm congenital AAA was diagnosed prenatally and was successfully treated 10 days after birth without exogenous graft material or aneurysmorrhaphy. Follow-up study at 39 months demonstrated excellent clinical, ultrasound scan, and computed tomography scan findings. Anatomic reconstruction with native vessels is the preferred surgical technique to ensure the child's potential for harmonious growth.