Primary infections of the aorta are rare. We recently treated a patient who was given a diagnosis of noninfectious aortitis after an extensive work-up, but after clinical deterioration, was found to have a pneumococcal mycotic aneurysm at the time of surgery. The difficulty in distinguishing microbial aortitis from noninfectious chronic periaortitis is discussed as well as the need for frequent surveillance imaging of the aorta if immunosuppression is used to treat the latter entity. The infected aortoiliac segment was ultimately repaired with autologous femoral veins.