The number of youth under juvenile justice supervision decreased by approximately 5 percent in the period 2000-01 to 2003-04. Approximately 12,900 youth throughout Australia received juvenile justice supervision each year, including approximately 10,000 who were ages 10-17. Almost two-thirds of the youth were at least 15 years old when they had their first period of juvenile justice supervision. Most youth completed one supervision period during a year, with community-based supervision being more common than detention-based supervision. Supervision periods of medium or longer lengths were more likely to include custodial sentences or community-based supervision. Males composed approximately 83 percent of those under supervision each year. Differences in the length and type of supervision were found to be linked to demographics such as age, sex, and Indigenous status. Just over 59 percent of detentions in 2003-04 ended with the youth being released on bail. Less than 10 percent of the detentions lasted through sentencing followed by an immediate incarceration period. Females were consistently more likely than males to be released on bail, and non-Indigenous youth were more likely than Indigenous youth to be released on bail. The average daily number of detainees in juvenile detention centers during 2003-04 was 792. 59 tables, 4 references, and appended juvenile justice legislation, key elements of juvenile justice systems in each State and Territory, a list of remand and detention centers, and national appendix tables