Nineteenth-century American reformers were concerned about the influence of immaturity and development in juvenile offenses. They responded to their delinquent youths through the creation of juvenile courts. This early American juvenile justice system sought to treat children as different from adults and to rehabilitate wayward youths through the state's assumption of a parental role. Although these rehabilitative goals were never fully realized, the field of American child psychiatry was spawned from these efforts on behalf of delinquent youths. Early child psychiatrists began by caring for juvenile offenders. The function of a child psychiatrist with juvenile delinquents expanded beyond strictly rehabilitation, however, as juvenile courts evolved to resemble criminal adult courts-due to landmark Supreme Court decisions and also juvenile legislation between 1966 and 1975. In response to dramatically increased juvenile violence and delinquency rates in the 1980s, juvenile justice became more retributional, and society was forced to confront issues such as capital punishment for juveniles, their transfer to adult courts, and their competency to stand trial. In the modern juvenile court, child psychiatrists are often asked to participate in the consideration of such issues because of their expertise in development. In that context we review the role of psychiatrists in assisting juvenile courts.