Three counties were selected to represent urban, suburban, and rural areas of Illinois' juvenile justice system. Data were collected between 1995 and 1996. The final sample consisted of 473 petitioned, adjudicated, and incarcerated cases. The sample was 34.2 percent African-American, 29.8 percent Caucasian, 14.2 percent Hispanic, 3 percent Native-American, 2.7 percent Asian or "other," and 18.8 percent of unspecified race. Clinical data were obtained from case records by using the Childhood Severity of Psychiatric Illness Scale, which assesses the mental health needs of children and adolescents on a variety of dimensions, including symptoms, risk behaviors, functioning, comorbidity, caregiver capacity, and multisystemic needs. Demographic, social, and service-history data were collected from the juvenile court records and case records. The Statistical Package for the Social Sciences version 10.1 was used to analyze all data. Although mental health needs were evident across the sample, there were differences in the types and severity of mental health needs by race. Overall, African-American youth had the highest level of mental health needs compared to Caucasian and Hispanic youth. African-American youth were underserved compared to Caucasian and Hispanic youth, given their high rates of symptoms, functioning, and comorbidity needs. Caucasian youth had the highest rate of current and prior mental health service use, and Hispanic youth received the least amount of current and prior mental health treatment. Hispanic youth had significantly more severe symptoms of conduct disorder and criminal delinquent behavior than Caucasian youth, but had a rate similar to African-American youth. Although comparatively well-served, Caucasian youth were probably underserved as well, given their high rate of psychiatric symptoms and substance abuse, as well as low rate of prior treatment. 4 tables and 49 references