The management of mycotic aneurysms and prosthetic graft infection of major thoracic and abdominal vessels and infected extra-anatomic bypass remains a problem in vascular surgery. Cryopreserved arterial homografts, being resistant to infection, offer hope for in situ vascular reconstruction in the presence of an infection. We analyzed clinical, microbiological, preoperative and postoperative magnetic resonance imaging (MRI), computed tomography (CT), echocardiography and/or angiography data in 12 patients with mycotic aneurysm or prosthetic graft infection, in whom cryopreserved arterial homografts were used to replace infected segments of major thoracic and abdominal vessels. The hospital mortality was 8.3%. The average postoperative hospital stay was 18 +/- 14.5 days (6 to 45); antibiotic treatment was continued for 31 +/- 12 days (4 to 42). During the mean follow-up time of 18.6 +/- 12.8 months (2 to 48) two patients died, but only one (9%) was homograft-related. Recurrence of infection, suture line problems or homograft stenosis or aneurysm were not observed. Therefore, in situ replacement with cryopreserved arterial homografts is an effective treatment for mycotic aneurysms and graft infection of thoracic aorta, abdominal aortic/iliac vessels and infected extra-anatomic bypass. This operative technique has a low early and late mortality, obviates the need for complex extra-anatomic reconstruction, allows safe in situ repair, reduces postoperative antibiotic requirements, shortens the hospital stay and renders early or medium-term reoperations unnecessary.