In order to better respond to the needs of adolescents in custody in New South Wales, the Department of Juvenile Justice (DJJ), the Corrections Health Service (now Justice Health), and the University of Sydney conducted a survey of 242 young people in custody to discover what they are like. Of the 223 males and 19 females who participated, many had highly unstable backgrounds and presented with at least some symptoms of mental and physical health problems. In terms of family background, 28 percent of participants had a history of living in care, 19 percent were living with a person who has a physical or mental health problem, 34 percent were not living at home prior to custody, 66 percent reported some form of child abuse or neglect, 20 of males and 45 percent of females endured emotional abuse, and 21 percent of males and 23 percent of females had suffered physical abuse. Standard mental health assessments found that 84 percent of the participants presented with mild, moderate, or severe symptoms consistent with a clinical mental health disorder. A full 55 percent presented with symptoms consistent with two or more clinical disorders, most often substance abuse disorder and conduct disorder. A high percentage of the group also reported engaging in health-related risk behaviors, such as unprotected sex, alcohol and other drug use, and attempted suicide. Implications of the findings are discussed in terms of how the juvenile justice system can better meet the considerable service needs of young people in custody. A plan for future study is explicated. Table, endnotes