Teacher leaders, who are stakeholders in the school and implement policies designed to improve student achievement, are a crucial part of educational reform efforts. However, the responsibilities of teacher leaders vary widely at the site level. Teacher leaders' self-efficacy must be substantive in order for them to enact change. This quantitative study provides essential findings in developing and building teacher leaders by identifying specific leadership responsibilities that positively influence teacher leaders' self-efficacy. Two major research questions drive this study How do teacher leaders perceive their self-efficacy? What conditions influence teacher leaders' self-efficacy? California teacher leaders (n=121) took a three-part survey adapted by the researcher from Tshannen-Moran and Gareis's 2004 Principals' Self-Efficacy Scale, organized into three subcategories (management, moral leadership, and instructional leadership). Another section of the survey asked about workplace conditions, and the final section asked about school structure. Descriptive statistics, correlations, and stepwise regression revealed that workplace conditions (professional development, collaboration time, decision-making, physical space, and rewards) were predictive of teacher leaders' self-efficacy. There was a small negative correlation between self-efficacy and student enrollment. Results from this study can be used to inform administrators and school leaders who have a significant role in creating the culture and school structure that foster both established and future teacher leaders. Recommendations at the policy level include promoting teacher leader standards, and clarifying roles and responsibilities, to better articulate workplace conditions. [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.]