A retrospective cohort study was undertaken to determine the prognostic significance of Staphylococcus aureus bacteriuria in patients presenting to our hospital with S. aureus bacteraemia between January 2000 and December 2003. A total of 378 patients had at least one positive blood culture for S. aureus, of whom 221 had urine cultured within 24h of presentation. For this group, 206 case records could be retrieved for review. Of these patients, all had meticillin-susceptible S. aureus bacteraemia and 35 (17%) had S. aureus cultured in urine. Logistic regression analysis was used to control for age, genitourinary tract status and comorbidity. Concomitant S. aureus bacteriuria persisted as a significant risk factor for ICU admission [risk ratio (RR): 2.5; 95% confidence interval (CI): 1.06-4.36; P=0.04] and in-hospital mortality (RR: 2.18; 95% CI: 1.05-3.57; P=0.04). Other findings were that cerebrovascular disease in males and increasing age in both sexes were associated with in-hospital and one-year mortality. Prospective studies are warranted exploring the link between S. aureus bacteriuria and clinical outcome in patients with S. aureus bacteraemia.