Disparities in school discipline for Black students has been a problem for decades. The negative effects of exclusionary discipline have been well-documented. This problem must be addressed by educational stakeholders in order to take steps to reduce the issue and provide interventions to reduce the disproportionality. Disproportionality in discipline prevents schools from achieving the ultimate goal of fostering positive outcomes for all students. School-Wide Positive Behavioral Interventions and Support Programs have created a systems-level approach to reducing overall school discipline issues. Some studies have identified SW-PBIS programs that have been able to reduce disparities in secondary schools and increase graduation rates, however, studies of SW-PBIS and disproportionality have overlooked disparities in elementary schools. The present study contributed to the current research base by investigating elementary disparity rates and how schools are using a SW-PBIS system to lower those rates. It also identifies factors that create strong programs successful in reducing disparity rates as well as factors that hinder the success of schools with disparity problems. This qualitative analysis revealed four themes that are critical to the success of a SW-PBIS system in lowering disparity rates: training, finding the root of the negative behavior, high expectations, and support for teachers. Implications for professional development, data tracking, and measuring disproportionality in schools are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]