Mycotic aortic aneurysm continues to present challenging and difficult management issues with a significant morbidity and mortality. The offending organism in the etiology of this aneurysm can be variable and unusual. The first report of two mycotic aortic aneurysms caused by Clostridium septicum in the same patient is described here. Presentation and management as well as conditions commonly associated with Clostridium septicum infection and a review of all clostridial mycotic aortic aneurysms in the English literature are discussed.