This study examined the effect of School-wide Positive Behavior Support (SWPBS) on bullying using a quasi-experimental, pretest and posttest nonequivalent groups design. Student self-surveys were used as a measure of bullying at pre- and posttest intervals during a school year to identify changes in student perceptions of school climate and rates of bullying in a school implementing SWPBS and a control. The researcher examined the following four hypotheses: Compared to a control school, students in a school implementing SWPBS will report (a) a decrease in the frequency of bullying; (b) improved perceptions of school climate; (c) increased victim willingness to seek help; and (d) increased bystander willingness to intervene or notify an adult. Results of all four analyses were not statistically significant, indicating that SWPBS did not significantly reduce bullying, improve school climate, increase victim willingness to seek help, or increase bystander willingness to intervene as measured by this study.