This article discusses School-wide Positive Behaviour Support (SWPBS), an evidence-based approach to teaching social competencies and enhancing the school social environment. The focus of this article is on the value of evaluation and evaluation plans at a district level for maintaining and increasing the effectiveness of SWPBS in a district. We review the key components of evaluation plans and describe a framework for creating evaluation plans created for British Columbia. We also provide an example of the evaluation efforts using this framework in a medium sized school district in British Columbia. Results showed decreased levels of problem behaviour, decreased numbers of students at risk for significant behaviour challenges, and increased academic achievement and student perceptions of school safety for schools implementing SWPBS, in comparison to low implementing schools and district and provincial averages. (Contains 6 figures.)