Although neuropsychological assessments provide valuable information for those working in forensic mental health, few neuropsychological studies concern persons who sexually offend, particularly juveniles who have sexually offended (JSO). It has been suggested that, contrary to current theories, executive function in JSO, as a group, is no more impaired than it is in juvenile delinquents in general. However, JSO with child victims seem to be more impulsive than JSO whose victims are peers or adults. To verify this potentially important (and unexpected) finding, a sample of adolescent males ( N = 134; 15.6 ± 1.5 years old) that included JSO, general delinquents, and underprivileged nondelinquents was assessed using a battery of behavioral and psychological tests that focus on impulsivity. No difference was found between groups regarding higher order executive functions as measured with the Wisconsin Card Sorting Task but JSO with child victims were found to be the most impulsive subgroup as evidenced with the Iowa Gambling Task, the Stop-Signal Reaction Task, and the Impulsive scale of the Social Problem Solving Inventory. They also had the highest number of prescriptions for attention deficit hyperactivity disorder (ADHD) medication. These results, which contradict hypotheses derived from assessment of adult sex offenders, illustrate an important difference between the cognitive profiles of adult and juvenile males who sexually offended. They also confirm that JSO whose victims are children appear to be more impulsive.