Staphylococcus aureus bloodstream (SAB) infections are common and serious causes of morbidity and mortality. They also cause considerable additional healthcare costs. In Australia, there are ~7000 SAB infection episodes per year and most of these are associated with healthcare procedures. In hospitals, data on all S. aureus bacteraemia episodes are relatively easy to collect. Collecting this data gives an accurate indication of the incidence of SAB infection in individual hospitals and whether they are healthcare-related infections (e.g. arising from intravenous catheter infections or surgical sites). These data also measure the relative proportion of methicillin-resistant S. aureus infections. When hospitals investigate the causes of individual healthcare-associated SAB infections, preventable factors will be identified. This should result in changes in clinical practice and protocols, while ongoing surveillance will allow an assessment of the efficacy of control measures. This will result in a decrease in the number of serious and life-threatening infections. This article is an abridged version of Chapter 2: ‘Bloodstream infections’ from the publication ‘Reducing harm to patients from health care associated infection: the role of surveillance.’ Cruickshank M, Ferguson J, editors. Sydney: Australian Commission on Safety and Quality in Health Care; 2008. The complete publication is available online at: www.safetyandquality.gov.au.