BACKGROUND: Mortality in patients with infected aortic aneurysms remains high. A number of patient- and infection-specific risk factors for death have been proposed, but none is consistently predictive of poor outcomes. The purpose of this study was to examine the possible contribution of infection-related risk factors and the systemic inflammatory response syndrome (SIRS) to outcomes of patients with infected aortic aneurysms. STUDY DESIGN: Ten patients with infected aortic aneurysms presenting to our institution over a recent 6-year period were studied. Collected data included aneurysm location, culture results, preoperative indicators of SIRS, operative details, and outcomes. RESULTS: Common presenting symptoms included abdominal or back pain and fevers. Aneurysms involved the thoracoabdominal aorta in four patients, the suprarenal aorta in one, the juxtarenal aorta in one, and the infrarenal aorta in four. Seven patients met criteria for SIRS. Repairs included in situ replacement of the infected aneurysm using rifampin-soaked, gel-impregnated Dacron in four patients with thoracoabdominal aneurysms and using autogenous superficial femoral-popliteal vein in five patients with infrarenal aneurysms. Four patients died of sepsis, and six patients survived to discharge after a mean of 23 ± 12 days in the hospital, followed by extensive rehabilitation. The combination of SIRS and suprarenal extension was present in all four patients who died. CONCLUSIONS: Although rare, infected aortic aneurysms are associated with marked morbidity and mortality. Sepsis is the leading cause of death. A combination of host- and infection-specific variables may be more predictive of outcomes than any single risk factor. Prolonged hospitalization and extended rehabilitation are frequently required in survivors, but longterm outlook is good after successful treatment.