A critical step in addressing a call for schools to use curricula such as problem-based learning (PBL) is developing an understanding of how school leaders can support its implementation. The purpose of this study was to examine ways school leaders at a comprehensive, public high school provided supports to teachers as they implemented this student-centered instructional approach school-wide. A single case design was used to investigate the supports the school leaders at a comprehensive, public high school serving a diverse group of students used to facilitate school-wide implementation of PBL. Data collection took place during three site visits totaling seven weeks over the course of a school year. Data sources included semi-structured interviews, focus groups, relevant documents (e.g. meeting agendas, professional development plans) and artifacts (e.g., meeting notes, work products). Data was analyzed using thematic analysis. The first research question addressed the supports implemented by the principal to facilitate the transition to PBL. Findings indicated that principal provided supports connected to seven domains: Alignment and Coherence; Capacity Development; Culture; Curriculum, Instruction, and Assessment; Data-Informed Decisions; Relationships and Strategic Partnerships, and; Resource Management. The second question addressed the teacher and teacher leaders' perspective on the supports provided. Findings suggested that supports related to: (a) the development of a PBL framework used in the design, implementation, and evaluation of problem-based curriculum; (b) ongoing, teacher-led professional learning focused on the PBL framework, (c) efforts to transform school culture through the use of collaborative teacher design teams, and; (d) fostering innovation were largely successful. The final research question addressed what additional supports were needed or desired by the teachers. Findings suggested that teachers wanted: (a) additional collaborative time to plan, develop, revise curriculum, as well as observe other teachers; (b) additional time to develop partnerships with outside experts, and; (c) better training and support for new and novice teachers. Suggestions for future research are also 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.]