Background: In an ageing population, older people comprise an increasingly higher proportion of emergency department (ED) presentations. When admitted to hospital, some elderly patients (particularly aged care facility residents) are at risk of iatrogenic complications. Method: A retrospective cohort study was conducted to describe clinical characteristics and predict outcomes of 6208 patients aged =65 years who presented to one emergency department (ED) from 1 July 2002 to 30 June 2003. Internal comparisons of aged care facility residents (ACFRs) and non-aged care facility residents (non-ACFRs) were performed. Outcome measures included length of stay (LOS) (ED and hospital), ED re-presentation, hospital readmission and in-hospital mortality. Results: 1006 ACFRs and 5202 non-ACFRs presented to the ED within 12 months. Compared to non-ACFRs, ACFRs comprised significantly higher proportions of admission (76.6% vs. 60.8%), ED re-presentation (66.0% vs. 52.0%) and hospital readmission (36.5% vs. 24.7%). ACFRs also had a significantly longer ED LOS (6 h vs. 5 h) and hospital LOS (5 days vs. 3 days). Multivariate analysis revealed that ACFR was an independent predictor of an ED LOS of >6 h (OR 1.71, 95% CI 1.54-1.92, p < 0.001), re-presentation to the ED (OR 1.67, 95% CI 1.45-1.93, p < 0.001), hospital LOS of > 6 days (OR 1.31, 95% CI 1.13-1.51) and hospital readmission (OR 1.76, 95% CI 1.49-2.07). Conclusions: Older people presenting to the ED, particularly ACFRs, are a group susceptible to negative hospital related outcomes. These outcomes should be considered by health service planners given the expected growth in the older population and subsequent need for acute medical services.