Objective: Analyze diagnostic and demographic factors to identify predictors of delinquency resulting in incarceration within a group of children/adolescents diagnosed with ADHD. Method: The study followed a cohort of 15,472 Medicaid covered children/adolescents with ADHD, ages 6 to 15 inclusive, between January 1, 2003, and December 31, 2006. The Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev. [DSM-IV-TR]), 2000 Codes were used for qualifying diagnosis codes. Available demographic characteristics included race, sex, and residence. The outcome was incarceration at the South Carolina Department of Juvenile Justice during 2005-2006. Results: Among youth with ADHD, incarceration was more likely among black, male, and urban youth. Children/adolescents with comorbid ODD and/or CD were at greater risk compared with those with ADHD alone. Conclusion: Within ADHD-diagnosed youth, comorbid conditions and demographic characteristics increase the risk of incarceration. Intervention and treatment strategies that address behavior among youth with these characteristics are needed to reduce incarceration.