Alternative educational settings are serving students with emotional disabilities (ED) at an increasing rate; however, there a paucity of research examining the effectiveness of these programs. A review of the existing literature targeting students with problematic behaviors, supports the use of a positive, preventative, proactive, and systematic approaches such as the three-tiered, Positive Behavioral Interventions and Support (PBIS) framework. Although findings suggest that the PBIS framework is associated with favorable outcomes for students with ED in both traditional and nontraditional settings, few studies have explicitly examined whether PBIS can be effectively modified to fit the needs of students with ED in alternative education settings. As such, the current qualitative study aimed to address these gaps in the related literature by examining how and why PBIS was effective for students with ED in alternative education. A single case-study design was used to collect evidence of PBIS implementation for students in this population from the direct interviews of five staff members, archival school records, and PBIS-related documentation. Braun and Clarke's (2006) six-step thematic analysis was used to interpret data and develop themes, resulting in the emergence of three specific themes: 1) strategies and practices; 2) data tracking: measuring progress and outcomes; and 3) systems and structures. In addition, the case study team identified nine corresponding subthemes to support these themes. Findings illustrated the specific adaptations and modifications made to the PBIS framework, contributing to the effective implementation of the strategy and meeting the needs of students in the ED population. Findings of this study provided several implications for constituents and potential future areas of research. [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/en-US/products/dissertations/individuals.shtml.]