Abdominal aortic aneurysms (AAA) are permanent dilations in the infra-renal area in which the arterial tissue is characterized by inflammation and medial degeneration. AAAs are a common vascular disorder and cause significant mortality in the aged population. Despite the high prevalence of this disease, there is limited knowledge on the mechanisms responsible for the vascular pathology. Therefore, current therapeutic options are restricted to surgical intervention and are predicated on the assumed propensity for rupture as the vessel enlarges. Current research focuses on inflammatory processes and their role in proteolytic degradation of the elastin and collagen fibers of the vessel wall. Definition of specific mechanisms would identify target sites for potential pharmacologic intervention and markedly improve the medical treatment and prognosis of AAA.