The four groups were those who were ADD and delinquent, ADD only, delinquent only, and non-disordered. The factors correlated with delinquency were traced biennially across childhood and included antisocial behavior problems, verbal intelligence, reading difficulty, and family adversity. The boys who were both ADD and delinquent consistently had the worst ratings on the assessments of family adversity, verbal intelligence, and reading. Their antisocial behavior began before school age, escalated at school entry, and persisted into adolescence. The ADD-only boys had normal family, intelligence, and reading scores and showed only mild antisocial behavior in middle childhood. The delinquent-only boys showed no early risk from family, low intelligence, or reading deficit and remained relatively free of behavior problems until they began delinquent behavior at age 13. Because the boys who were both ADD and delinquent were similar to those in other research on juvenile-to-adult offending, it is anticipated that their criminality will persist beyond adolescence. Tables, figures, and 63 references (Author abstract modified)