Infected abdominal aortic aneurysm (IAAA) are rare, but life-threatening. This time we experienced six cases of infected abdominal aortic aneurysm. We measured the soothing of bacteremia by two weeks of antibiotic treatment before operation, if not in a state of impending rupture or rupture. The in situ prosthetic graft replacement surgery was the first choice. In five cases, we replaced by an in situ dacron graft with Rifampicin. However, one case that was by pondylitis caused by Helicobacter cinaedi was treated by extra-anatomical bypass. There was no post-operative infectious complication. In addition, surgery/hospital death was 0%.