Takayasu's arteritis or nonspecific arteritis is a term used to designate a primary arteries of unknown etiology involving the aorta and its major branches at any level. Generally, the lesions are obliterative; however, aneurysms and saccular dilations have also been described. The arteritis was originally believed to be limited to the aortic arch; however, involvement of the descending thoracic and abdominal aorta has been reported. In fact, the majority of cases of Takayasu's disease in children involve the descending thoracic and abdominal aorta. A case of Takayasu's disease in a 7-month-old black male infant involving the right common iliac artery with development of a large aneurysm and an iliocaval fistula is reported. This child is the youngest to be affected by the disease as reported in the literature. Although Takayasu's disease is rare, it should be considered in the differential diagnosis of children with an abdominal mass.