Thirty-nine consecutive Staphylococcus aureus bacteremias were reviewed with particular attention to complications. Thirty-four (87%) of the bacteremias were nosocomial, with intravascular catheters (20 episodes) and dialysis-access sites (six episodes) the most common sources. Complications developed in 36% (14/39) of all bacteremias and in 30% (6/20) of those that were catheter-associated. Acute complications (shock, adult respiratory distress syndrome, disseminated intravascular coagulation) occurred in six patients and were fatal in four. In nine patients metastatic suppurative complications developed, six at sites of preexisting abnormalities. There were no episodes of endocarditis. Most patients received prolonged antibiotic therapy, and the majority of all suppurative complications required surgical intervention. Staphylococcus aureus bacteremia, even when not associated with endocarditis, is a cause of considerable morbidity and mortality in hospitalized patients.