The purpose of this study is to explore the effects of school-wide positive behavior interventions and supports (SWPBIS) on student academic performance. The participants in the study are eight middle schools from an urban Southern California school district where the implementation of SWPBIS was mandated. Using archival data collected by the school district and information from the California Department of Education Website, multiple baseline trends were conducted. The findings revealed that when schools implemented SWPBIS, the student outcome data was positively impacted and this positive impact continues as schools continue to fully implement all components of SWPBIS. In schools where SWPBIS was implemented fully and the staff sustained the program at the school site, the growth in academic achievement was strongly associated with the implementation of SWPBIS with fidelity. Discussion centers on recommendations for educational leaders for implementing SWPBIS.