Population ageing is projected to impact on health services utilisation including Emergency Departments (ED), with older patients reportedly having a high rate of return visits. We describe and compare patterns in ED utilisation between older and younger adults, and quantify the proportion and rate of return visits. Methods: Population-based retrospective analysis of metropolitan Melbourne public hospital ED data, 1999/2000 to 2008/2009. Numbers of patients, presentations, re-presentations and rates per 1000 population were calculated, with comparison of older (aged 70 years) and younger (15?69 years) attendances. Results: Population growth in each age group was similar over the study period, yet ED presentations rose by 72 for older adults compared with a 59 increase for younger adults. Rates per 1000 population rose with increasing age. Of the population aged 70 years, 39 presented to ED compared with 17 of the population aged 15?69 years in 2008/2009. Twenty-seven per cent of the increase in older adult presentations was driven by a cohort who attended 4 times in 2008/2009. The number of older patients presenting 4 times doubled over the decade, contributing to 23 of all older presentations in 2008/2009. ED length of stay rose with increasing age; 69 of older adults remained in ED for 4 h compared with 39 of younger adults in 2008/2009. The number of older adult ED hospital admissions doubled over the decade. Conclusions: Older patients are disproportionately represented among ED attendances. They also have an increasing propensity to re-present to ED, indicating a need to identify the clinical, social and health system-related risk factors for re-attendance by specific patients.