A review of the Uniform Crime Reports for 1969-78 shows that 54.6 percent of arson arrestees were under age 18. Almost 43 percent were 13-19 years-old, and those 10 and under composed 11 percent of the total arrest population. Children under age 8 generally set fires at home, in closets, or in garages. Criminal motivation is rarely involved. Most school fires are started by boys between 9 and 12, with the motivation being revenge, spite, or the disruption of classes. Boys between 13 and 17 are responsible for over two-thirds of the Nation's vacant building fires. Regardless of age group, juvenile arsonists generally exhibit many personality characteristics common in adult pyromaniacs, notably, they are loners and have difficulty relating to adults and their peers. They frequently have bed-wetting problems and will not confess in the presence of more than one questioner but will repeat an initial confession to others. Youthful arsonists report having nightmares involving the devil and ghosts and an unusually rich fantasy life involving aggression and magical powers over adults. Serious child arsonists tend to show more fire-related responses to selected thematic apperception tests than children with a mild or no firesetting history. Young firesetters typically reside with disturbed families. Early intervention which uses the home and the school to develop positive adaptive behavior is most effective. Effective therapy depends upon the consistent application of new skills. Limited tabular data, three footnotes, and seven bibliographic listings are provided.