As the 21st century progresses, the role of the building-level school administrator has become more and more complex. With the demands of the No Child Left Behind Act, changing demographics, instructional leadership, and state accountability systems, the need for principals to feel a sense of efficacy toward their jobs is critical. There is a body of research that speaks to the role that efficacy plays in teacher classroom effectiveness; however, the literature does not that speak to the role that efficacy plays in the principalship. The purpose of this mixed methods study was to determine the role, if any, that efficacy plays in the principalship. Specifically, the study examined principals' ratings of their abilities to carry out the varied responsibilities of instructional leaders who can create successful learning environments. Using the Principal Self-Efficacy Survey developed by M. Tschannen-Moran and C. Gareis (2004b), the researcher sampled 113 principals in school districts in a metropolitan area of the Southeastern United States to gather their opinions about efficacy as it relates to instructional leadership. The results of the study revealed that principals on the high school level rated their belief in efficacy to perform the job higher than their counterparts at the middle and elementary school levels rated their belief. Also, female principals rated themselves more efficacious than their male counterparts rated themselves. The study also found that there was not a positive correlation between the adequate yearly progress status of a school and the level of efficacy of the principals. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]