We designed this study to evaluate a multi-institutional experience regarding the efficacy of cryopreserved aortic allografts in the treatment of infected aortic prosthetic grafts or mycotic aneurysms. We reviewed clinical data of all patients from 4 institutions who underwent in situ aortic reconstruction with cryopreserved allografts for either infected aortic prosthetic graft or mycotic aneurysms from during a 6-year period. Relevant clinical variables and treatment outcomes were analyzed. A total of 42 patients (37 men; overall mean age 63 +/- 13 years, range 41-74 years) were identified during this study period. Treatment indications included 34 primary aortic graft infections (81%), 6 mycotic aneurysms (22%), and 2 aortoenteric erosions (5%). Transabdominal and thoracoabdominal approaches were used in 38 (90%) and 4 patients (10%), respectively. Staphylococcus aureus was the most commonly identified organism (n=27, 64%). Although there was no intraoperative death, the 30-day operative mortality was 17% (n=7). There were 21 (50%) nonfatal complications, including local wound infection (n=8), lower-extremity deep venous thrombosis (n=5), amputation (n=6), and renal failure requiring hemodialysis (n=2). The average length of hospital stay was 16.4 +/- 7 days. During a mean follow-up period of 12.5 months, reoperation for allograft revision was necessary in 1 patient due to graft thrombosis (6%). The overall treatment mortality rate was 21% (n=9). In situ aortic reconstruction with cryopreserved allografts is an acceptable treatment method in patients with infected aortic prosthetic graft or mycotic aneurysms. Our study showed that mid-term graft-related complications such as reinfection or aneurysmal degeneration were uncommon.