The Longitudinal Study of Australian Children (Growing Up in Australia) is a large scale national study tracking the development of Australian children over the early years of life. The overall intent of the paper is to give readers a sense of the contribution that the Longitudinal Study of Australian Children (LSAC) will make, and what the study will offer to policy makers, researchers and service providers. This paper discusses the rationale for conducting such a study in Australia today. It outlines various overseas and past Australasian studies in order to highlight some of the key issues to be considered, and provides a broad overview of the study, including the conceptual model on which it is grounded and some of its key design features. The article discusses progress made in the 12 months since the contract was signed and the study's future plans and timelines.