This paper provides an overview of the extent of the ageing of the population in Australia and reviews the evidence and debates that have emerged over the extent of ageing and its consequences for social policy. After a brief historical account of ageing in Australia, the methods used by the Australian Bureau of Statistics (ABS) to project future population movements are described and the latest series of ABS projections are summarised. Particular attention is devoted to the debate over the impact of immigration on ageing and it is argued that the attention devoted to this contrasts with the relative neglect of several other important aspects of the issue. The paper then discusses in some depth the debate over the implications of ageing for social expenditure, drawing on recent work undertaken by the Economic Planning Advisory Commission (EPAC) and the National Commission of Audit. It is argued that the expenditure projections underlying this work are simplistic and fail to take account of the dynamic aspects of ageing and what these imply for the overall economic and social fabric of an ageing society. After providing a few illustrations of how Australian social policy has been responding to ageing, the paper finishes by providing some case study evidence which illustrates the kinds of difficulties encountered by those Australians who are trying to cope with the problems of old age.