The ageing of Australia's population has led to a focus on the health resources required for older patients, and there has been concern that this might be at the expense of children's healthcare. Over the past few decades the number of children in Australia has increased, but has steadily declined as a proportion of the population. This has paralleled an increase in the absolute number of general practitioner (GP) encounters with children aged <15 years, but a decline in the percentage of GP workload from 14.3% in 2000-01 to 11.2% in 2013-14. There are disparities in the use of general practice services by age, with children making up a greater proportion of the population (19.3%) than of GP visits (13.0%), while people aged 65 years and older accounted for 13.0% of the population and 26.5% of visits in 2006. It is unclear whether the decline in the proportion of GP workload accounted for by children reflects a change in the way children use these general practice services, or a redistribution based on the ageing of the patient population. Over time, there have been marked changes in the types of problems managed in children. From the 1990s to 2001, Australia's children became well vaccinated and decreasingly likely to have 'traditional' childhood illnesses (notably infections). More recently, there has been significant growth in the management of child mental health problems in general practice, although mental health problems account for a small proportion of childhood problems managed. We examined children's use of general practice services and the problems managed in 2000-03 and 2012-15 to determine whether their service use has been influenced by the demands associated with the management of older Australians, and whether trends in problems managed identified in early studies have continued.