An increasing need exists in the field of early intervention for effective approaches to address challenging behavior in early childhood settings. This need is driven by the growing number of preschool children reported to have challenging behavior and the increasing knowledge base about the long-term outcomes for children who engage in problem behavior during the early childhood years. Teachers report that challenging behavior is one of their highest priority training needs. A promising approach to addressing challenging behavior in early childhood settings is a program-wide system of positive behavior support (PBS). While a program-wide PBS model has been clearly articulated for use in elementary and secondary schools, relatively little attention has been given to program-wide models of behavior support in early childhood programs. The purpose of this article is to describe the essential elements of a program-wide model of positive behavior support that reflects an understanding of the needs of young children and the unique characteristics of early childhood settings (e.g., Head Start, public preschool, child care). The article also will provide an illustration of the adoption of the program-wide model by a rural Head Start program.