The Australian Institute of Health and Welfare (AIHW) has worked with the Australasian Juvenile Justice Administrators (AJJA) to develop nationally consistent data on juvenile justice supervision in the form of the Juvenile Justice national minimum data set (NMDS). The Juvenile Justice NMDS is based on the experience of the young person within juvenile justice supervision, making it somewhat different to other criminal justice collections that focus on legal orders. The data in this first report of the new NMDS cover the period 2000-01 to 2003-04, with the main focus of findings being on the latest year.