From 1 April 1983 to 31 October 1985, 114 episodes of Staphylococcus aureus bacteremia (SAB) were identified in 111 patients at the Buffalo Veterans Administration Medical Center. Only 14% of the episodes were community-acquired, and 29% were due to methicillin-resistant strains. The commonest foci of SAB were intravascular catheters (33%), postoperative wounds (11%), skin infections (7%), and pulmonary infections (7%). Complications were infrequent, with endocarditis in two patients and metastatic infection in one. Mortality due to SAB was 32%, with no difference in mortality between community-acquired and hospital-acquired SAB. Although not statistically significant, there was a trend of higher mortality for methicillin-resistant SAB (42%) than for methicillin-sensitive SAB (28%) and for patients with no focus of SAB (43%) than for those with a defined primary focus (28%). A review of studies of SAB published since 1940 revealed several trends. SAB is now predominately a nosocomial infection; intravascular-catheter infection has become the commonest cause of SAB; with several exceptions, the risk of endocarditis in patients with SAB is low (5%-20%); mortality due to SAB has decreased over the past 40 years but not over the past 10 years.