This study set out to explore how five principals experienced collective teacher efficacy in their schools. The uniqueness of this study was the context of collective teacher efficacy in urban turnaround schools. Each school in the study was once considered among the lowest performing schools in Massachusetts, with persistent low student achievement. These schools experienced accelerated student learning and reversed the trend of underperformance in a three-year period. An interpretative phenomenological analysis (IPA) provided the methodology to understand the complexity of teacher professional practice as experienced by the principals. The personal narratives of principals provided rich, detailed accounts for inductive analysis within the context of urban school turnaround environments. This study reveals that principals launched systems and structures to build collective teacher efficacy. The four sources of collective efficacy--mastery experience, social persuasion, vicarious learning experience, and affective states--were present in these various systems and structures. Specifically, principals created collaborative structures that enabled teachers to build their collective capacity. Through social persuasion, which included feedback that supported persistence and resilience, principals were able to enlist teachers' authentic participation in collaborative structures, such as common planning time or professional learning communities (PLCs). Findings also indicated that the collaborative structures created a social system within which teachers could exercise various forms of social, human, intellectual, and decisional capital. In turn, teachers built their collective capacity to improve student learning, as evidenced by student learning measures. As teachers exercised their professional capital, student learning increased and mastery experience was realized. Moreover, mastery experience contributed to a future-oriented perspective that performance would continue to be proficient. [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.]