Response to Intervention (RTI) is a multi-tiered system of support designed to provide increasing levels of intervention and enrichment based on student need. Research suggests that although RTI is regularly utilized in elementary schools, secondary school leaders are less likely to implement if due to the unique challenges of a secondary school setting. The purpose of this qualitative investigation was to examine RTI implementation in a high school. The theoretical framework for this study included Constructivist Learning Theory and Organizational Change Theory. The research questions sought to explore the perceived barriers and perceived essential components of secondary RTI implementation. Teachers' perceived RTI skills were analyzed through a comparison of pre-and post-professional development cycle surveys. Educators were interviewed to determine perceived essential components of professional development during initial RTI implementation. Data discussion of the findings would be beneficial for secondary school leaders seeking to implement RTI with their staff to increase student achievement. [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.]