The purpose of this case study was to examine the transition from junior high school to a middle school as experienced in two middle schools from a mid-sized urban school district located in the Rocky Mountains. The overarching question that guided data collection for this study centered on the factors that influenced school culture before, during, and after the transition from junior highs to middle schools as perceived by school leaders and teachers. Data were collected from the Middle School Teacher Survey, individual interviews and district artifacts. The study incorporated an intentional change theory. Results from the study showed that the schools had varied outcomes from the transition and the overall middle school culture. The conclusion of these outcomes varied within the district because of the site-based implementation of the transition. However, the results of the study showed that the district factor of leadership and organization, prior to the transition, with using empirical evidence, open communication with staff and the community, and a structured timeline for planning has proven successful in the sample studied. Within the case study, the perceptions of school leaders and school teachers provided evidence that one school did not transition as successfully as another within the middle school model and struggled with utilizing the factors from the study that ranged from leadership, cooperation, and teaming. [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.]