A substantial backyard has long been considered an iconic feature of the Australian suburb. Nevertheless, during the 1990s, a dramatic change occurred: substantial backyards largely disappeared from new suburban houses in Australia. Whatever the size of lot, the dwelling now covers most of its developable area. Although the planning system does not actually promote this change, it does little to prevent it. It appears to be a physical expression of the way that Australian lifestyles are changing for the worse, in particular longer working hours. This in turn raises issues about health and wellbeing, especially for children. Vegetation surrounding the dwelling plays an important role in microclimate, storm drainage and biodiversity, irrespective of whether the residents use their backyard. Its loss has serious ecological implications, a deficit rendered permanent by the changes to the housing stock. The Life and Death of the Australian Backyard is based on a detailed quantitative study of this increasing, but previously unstudied, problem. It discusses the nature, uses and meaning of the traditional backyard, presents an understanding of the changes that have been happening and suggests possible remedies. All professionals working in the landscape and development industries, local government, consultancies and in universities should read this unique study of an issue of increasing significance to urban sustainability.