This study compares adults with and without attention deficit hyperactivity disorder (ADHD) on measures of direct and displaced aggression and illicit drug use. Three hundred ninety-six adults were administered the Wender Utah Rating Scale, the Risk Behavior Assessment, the Aggression Questionnaire (AQ), and the Displaced Aggression Questionnaire (DAQ). Those with ADHD were higher on all scales of the AQ and DAQ, were younger at first use of amphetamines, and were more likely to have ever used crack and amphetamines. A Structural Equation Model found a significant interaction in that for those with medium and high levels of verbal aggression, ADHD predicts crack and amphetamine. Follow-up logistic regression models suggest that blacks self-medicate with crack and whites and Hispanics self-medicate with amphetamine when they have ADHD and verbal aggression.