This study is to examine if implementation of the universal level of PBS is related to student achievement on the LEAP and iLEAP examinations administered as part of the Louisiana Educational Assessment Program. A second purpose is to examine whether identified student/school characteristics contribute to any difference in academic performance. To address this question, it is necessary to take into consideration individual as well as school level factors that may act to facilitate or impede student achievement. Multilevel statistical models are ideally suited for research problems of this nature and will be the approach taken for this study. The present study sought to determine if a high level of implementation of PBIS at the school level had an impact on a student's academic scores based on high stakes test scores. Across the state of Louisiana, a schools' implementation level of PBIS did show evidence of change of a student's high-stakes test score from 2007 to 2008. However, it did not show a change from 2008 to 2009. In both 2 year spans, a previous year's academic test score and a school's percent of free and reduced lunch were both predictors in the model. In 2007-2008, a school's SET score was also a significant predictor in the model in all of the content areas, except for math. The findings from the multilevel model are consistent with other findings for the 3rd grade to 4th grade match. However, for the 4th to 5th grade match the absence of similar findings may reflect the fact that implementation scores were mandated at the state level for these years, which may have caused inflation in scores from each school. Even in the correlations, the 2008 scores were not statistically significant as the 2007 scores were found to be. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]