The school-wide application of positive behavior support (PBS) is a prevention-oriented approach to student discipline that is characterized by its focus on defining and teaching behavioral expectations, rewarding appropriate behaviors, continual evaluation of its effectiveness, and the integration of supports for individuals, groups, the school as a whole, and school/family/community partnerships. Although school-wide PBS has been implemented in hundreds of schools thus far, many professionals in education and psychology remain, for the most part, unfamiliar with this proactive alternative for increasing positive student behavior. This article reviews the foundations and core components of school-wide PBS, provides a case example of the implementation and preliminary evaluation of school-wide PBS in an urban middle school, and summarizes critical issues and future research directions in this area of considerable importance to professionals in educational psychology and related fields.