This article describes the quantitative findings from an evaluation of program-wide positive behavioral interventions and supports (PBIS) in three rural preschool programs. Each rural preschool program included children 3 through 5 years of age with and without disabilities. Following 3 years of on-site training, technical assistance, and coaching support in universal tier PBIS, participating preschool programs increased their use of strategies and supports to prevent young children's challenging behavior. Specific improvements in universal PBIS practices are presented across each year of the initiative. The successes and challenges involved in implementing program-wide PBIS in rural preschools are discussed.