With demands for producing results in education, the problem for many teachers is accepting and implementing mandated changes. This study sought to determine the relationship between high school teachers' perceptions of change and change implementation at a rural high school in a southeastern US state. This study was based on planned behavior theory, which indicates that individuals deliberately complete an act based on their perceptions. This study was guided by an inquiry into high school teachers' perceptions of implementing change in their classrooms, including the factors that promote or hinder change. A qualitative, case study approach including surveys, interviews, and examination of documents was used to determine how 25 teachers' perceptions influenced their implementation of mandatory changes. Data were analyzed using inductive coding to identify emerging themes. Key findings indicated that teachers successfully implemented change when they took ownership of the change and believed they were trusted as professionals. Teachers were unsuccessful in implementing change when change in policies or procedures occurred or numerous changes occurred at one time. It is recommended that in order for successful change implementation to occur, administrators should solicit teachers' input based on their knowledge, good judgment and workload in order to meet rising education requirements. Results of this study hold potential to provide insights into change implementation in schools and school districts. This may have positive social change by identifying those factors related to change implementation and their impact on school reform. Findings of this study might be used to develop professional development for teachers where schools desire to incorporate change implementation to raise academic results. [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.]