Transient bacteremia leading to hematogenous infection of atherosclerotic vessels is the most common cause of mycotic aneurysms. Salmonella species, which are especially potent pathogens, often are the infecting organisms. A high index of suspicion is the cornerstone of diagnosis. Patients with salmonella cultured from the sputum, blood, or urine without adequate explanation must be suspected of intravascular infection. Surgical intervention with adjuvant ampicillin therapy should be expediently initiated after diagnosis. Provided no gross infection exists and prompt debridement and drainage are obtained, an "in situ" interposition graft is adequate. A ring graft has the advantage of allowing a shorter cross clamp time and eliminates the risks inherent in contaminated anastomotic suture lines. Prolonged, possibly life-long, antibiotic therapy offers the best prognosis for this disease after surgical repair.