This multiple case study was designed to examine the facilitating factors and barriers of the PBIS implementations from the perspectives of the administrators and PBIS coaches. Three middle schools, three administrators and three PBIS coaches in a school district in Florida participated in 30-40 minute interviews. Within-case analysis and cross case analysis were conducted to answer the main research question: What are the facilitating factors and barriers of PBIS implementation from the perspectives of the administrators and the PBIS coaches? The cross-case analysis identified two facilitating factors to the PBIS implementation: (1) Strong Administrative Support, (2) Having an organized infrastructure. In addition, the cross-case analysis identified the three major barriers to the PBIS implementation: (1) Lack of District Support, (2) Lack of Financial Resources, (3) Lack of Teacher Buy-in. Due to the small sample size, though the study is not generalizable, the results correlated with the previously conducted study which strengthens the validity of the study. [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.]