Abdominal aortic aneurysms have usually been characterized as atheroslcerotic, but this view of their pathogenesis is a restricted one. As yet, no unified concept of pathogenesis has emerged, bat several factors appear to have an important role, including familial clustering, genetically determined and acquired biochemical alterations in the structural matrix of the aortic wall and bemodynamic mechanical factors. We review literature data concerning new pathogenic concepts of abdominal aortic aneurysms and particularly familial predisposition. Ultrasonographic screening is recommended in brothers (50 years) of patients with aneurysms of the abdominal aorta.