Abstract Takayasu's arteritis is a type of primary systemic vasculitis that affects medium and large arteries, including the aorta and its main branches, as well as the pulmonary and coronary arteries. Although rare in children, it is the third most common vasculitis in the pediatric population, often with delayed diagnosis due to the nonspecific presentation of clinical symptoms in its initial phase. This is a case of a 16-year-old girl with a giant ruptured abdominal aortic aneurysm, who needed surgery on an emergency basis. The etiological aspects involved in aneurysms in young patients are also addressed.