Four patients with mycotic aneurysm of the extracranial carotid artery, the innominate artery, the ascending aorta, and the infrarenal aorta were treated with local implantation of antibiotic-releasing carriers after resection of the aneurysm, excision of all infected tissue, and in situ reconstruction by prosthetic graft replacement in two patients and patch plasty in two patients. The patient with a mycotic aneurysm of the ascending aorta was operated on again 1 month after the first operation because of a second mycotic aneurysm located on the aortic arch. No early or late signs of recurrent infection were seen on clinical and laboratory postoperative follow-up done between 9 and 16 months or on duplex scan or computed tomography done at these times. Implantation of antibiotic-releasing carriers after debridement of all infected tissue and in situ reconstruction for treatment of mycotic aneurysm was performed successfully in four patients with this life-threatening condition.