The purpose of this study was to explore the impact of high-stakes testing and accountability on teachers' perceptions of their professional identities. Teachers' instructional practice, work environments, and personal factors are now immersed in the context of high-stakes testing and accountability. This context colors the decisions teachers make about instructional practice, the degree to which they collaborate with colleagues, and their emotions. Through a symbolic interactionist lens, this study explored how teachers give meaning to the influence of high-stakes testing. This qualitative study employed a semi-structured interview format to gather data from 11 Algebra I teachers in North Carolina on their perceptions of their professional identities. A conceptual framework based upon Bandura's social cognitive theory provided the foundation for exploring how teachers' instructional practice, work environment and teacher efficacy interacted and how these factors shaped teachers' professional identities. Context and demographic data were gathered through a questionnaire and the North Carolina School report cards. Based on interview data, researcher logs, and analytic memos, a vignette was developed about each teacher to explore the interactions of the teacher's instructional practice, work environment, and teacher efficacy. This study found most teachers relied heavily on direct instruction for reasons they attributed to high-stakes testing and accountability pressures, even when they believed other methods were better for their students. Related to this finding is the potential narrowing of teachers' role and purpose in their work as the influence of high-stakes testing and accountability interacts with their professional identities through their instructional practice, work environment, and teacher efficacy. Teachers expressed their professional identities in ways that positioned their identities in a student focus, or a teacher focus, whether peer or self. There appeared to be a relationship between whether teachers taught prior to the implementation of the NC ABCs and NCLB and the influence of this context on their professional identities. The teachers who expressed their professional identities in a student focus exhibited high perceptions of their teacher efficacy. Also, teachers' professional identities themselves mediated the way teachers experienced the influence of high-stakes testing and accountability. Principals and their actions influenced the way teachers constructed their professional identities. Of the teachers who reported principals as the primary source of the high EOC emphasis in their schools, four of the five teachers positioned their professional identities in a strong teacher focus. Principals played a primary role in the ways that teachers experienced and interacted with the context of high-stakes testing and accountability within their schools. The actions of the principals, both explicit and implicit, were a cogent influence in the construction of teachers' professional identities. [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.]