Studied official arrests from childhood through adolescence in 2 groups of boys: One group of 110 Ss was diagnosed in childhood as suffering from attention deficit disorder (ADD), and the other group of 88 Ss consisted of normal controls. Mean ages at follow-up were 17.3 yrs for the ADD group and 16.9 yrs for the controls. Rates of single and multiple serious offenses and of institutionalization for delinquency were significantly higher in the ADD Ss. Findings suggest a strong relationship between childhood ADD and later arrests for delinquent behavior. It is hoped that identification of children at high risk of becoming delinquent will facilitate intervention.