The use of SWPBS has increased quite rapidly across schools. This is happening against a backdrop of enthusiasm among policymakers, researchers and practitioners about the use of evidence-based practices in school settings. As SWPBS continues to attract the interest of school personnel it is necessary to look at this approach and examine its evidence base. This study was an attempt to extend previous work to that effect. Like previous efforts, this study demonstrated that although SWPBS has become quite popular, the evidence base may still be classified as promising. Research on SWPBS has to address many methodological limitations to strengthen its evidence base. (Contains 3 tables.)