Though research has validated a link between principal leadership and student achievement, questions remain regarding the specific relationship between the principal and high-achieving learners. This association facilitates understanding about forming curricular decisions for high ability learners. The study was conducted to examine the perceived roles of elementary principals as instructional leaders. Three research questions guided the study: (a) What is the elementary principals' perceived role as an instructional leader to facilitate differentiated curriculum to challenge high ability students?, (b) What is the teachers' perceived role to differentiate curriculum to challenge high ability students?, and (c) What are the teachers' perceptions of their principal as the instructional leader to facilitate differentiated curriculum to challenge high ability students? The mixed methods study was conducted in a suburban community serving 11,900 students. The primary source of data collection utilized a quantitative survey designed by the researcher for the purposes of this study. Ten principals and 32 fourth and fifth grade teachers serving 10 school sites participated in the survey. The second phase of the study included interviews with the principals to enhance the survey-related quantitative data. Perceived principal leadership, perceived principal support, and perceptions of student ability emerged as critical factors. Perceived principal leadership was explored through various elements, illustrating a strong tie to the importance of vision, and weaker ties to direct assistance with curriculum, instruction and assessment. Perceived principal support for a differentiated curriculum for high ability students was characterized by a discrepancy between principal support and provisions, and teacher needs. Findings also revealed a relationship between perceived principals' support for differentiation, and their perceptions of students identified with high ability. The findings suggested implications leading to a cycle of inquiry to foster policy development, curriculum modification, personnel selection, and training, in order to develop the principal as an instructional leader for teachers of high ability students. [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.]