Background: The aim was to document the spectrum of present and lifetime psychological disorders in female juvenile offenders, and to examine the relations between mental health status and socio-demographic, family and trauma variables. Method: One hundred juvenile offenders were matched with a comparison group of 100 females on age and socioeconomic status (SES). Psychological profiles and trauma histories of both groups were assessed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime Version (K-SADS-PL) and family functioning was assessed with the Family Adaptability and Cohesion Scale II (FACES II) self-report measure. Results: Rates of psychopathology were higher for offenders than non-offenders (p less than 0.001), with particularly high levels of conduct disorder (91% v.1%, p less than 0.001), substance abuse disorders (85% v. 5%, p less than 0.001), depression (55% v. 25%, p less than 0.001) and posttraumatic stress disorder (37% v. 4%, p less than 0.001). In the offenders, 78% met the criteria for three or more diagnoses. The number of psychiatric diagnoses was the most significant factor associated with offender status (OR = 21.26, p less than 0.001). Conclusions: There is a high prevalence of psychological disorder in females in juvenile justice custody and this has a very strong association with offender status. Because these co-morbid disorders are treatable, there is a clear opportunity to intervene to decrease psychological distress.