Despite advances in antimicrobial therapy and intensive care support, Staphylococcus aureus continues to cause significant morbidity and mortality. We studied community-acquired S. aureus bacteraemia in a population where intravenous drug abuse is extremely uncommon, prospectively reviewing all such patients (n = 113) admitted to Groote Schuur Hospital from February 1986 to January 1991. Overall mortality was 35%. Factors associated with poor outcome were: confusion on presentation, failure to mount a febrile response, acute renal failure, adult respiratory distress syndrome, shock, endocarditis, disseminated intravascular coagulation and platelet count of < 100 x 10(9)/l. Only confusion, acute renal failure and shock were independently associated with death by stepwise regression analysis. Skin infections were the most commonly identified source of bacteraemia (22%), but in 58% of patients the source was not determined. Twenty-six percent of patients were diabetic. Almost all patients (90%) developed one or more complications. In those who survived, therapy was generally prolonged, with a median of 70 days and range of 7-393 days, depending on the associated complications. Community-acquired S. aureus bacteraemia is a serious condition associated with a high complication rate and mortality.