This chapter provides an overview of positive behavior support (PBS) as an approach for addressing the challenging behaviors of children with autism. PBS is based largely on the principles and procedures of applied behavior analysis. The chapter begins by describing autism and PBS. It introduces a comprehensive, multilayered model for preventing and intervening with challenging behaviors. The chapter discusses five issues that are important for any consideration of prevention and intervention regarding challenging behaviors of young children with autism spectrum disorder (ASD). The guidelines and recommendations are based on collective experiences of the authors in implementing strategies designed to improve outcomes for children and their families. The five categories of implementation guidelines include: need to focus on family systems and family support; need for a collaborative approach and contextual fit; need for longitudinal perspective; issues concerning dosage, intensity, and engagement; and data-based decision making and accountability.