Outlining the beginning of behavioral treatment of children, this article describes the early experimental work on behavior analysis, with its inherent promise and limitations. Challenges to this early work promoted an even more promising technology for behavior therapy with children. Attention to several considerations drawn from past research is needed to enhance behavioral techniques, including attending to the complexity of the child's world, the child's developmental level, the unique demands of adolescence, and the powerful role of preventive interventions. Promises that remain to be fulfilled and future challenges to research and treatment are considered, with particular attention to the need for strong child advocacy.