A traumatic pseudoaneurysm of the abdominal aorta is a rare entity, occurring as the result of a missed aortic lesion at the time of the initial injury. Therefore, clinical suspicion and careful abdominal exploration at first laparotomy is mandatory to prevent aortic pseudoaneurysm formation and its risk of delayed rupture. We present a case of successful surgical treatment of a suprarenal aortic false aneurysm, presenting 4 weeks after a life-threatening gunshot wound in a 13-year-old child.