High levels of teachers' self-efficacy have frequently been recognized as a main quality of effective teachers. The problems investigated by this study stem from the lack of research about the relationship between professional learning community variables and Iranian EFL teachers' self-efficacy. Uncovering these relationships might have numerous implications for the ministry of Education, schools, and planning of growth opportunities for teachers. To address this considerable gap, in a mixed-method research, this study explored the capacity of the six components of professional learning community in relation to participating Iranian EFL teachers' self-efficacy, measured through their Teacher Sense of Efficacy Scale (TSES). On this matter, both quantitative and qualitative data collection and analysis were conducted. Quantitative data were collected from 122 teachers working at public schools in Sanandaj, Baneh, Kermanshah, Qhorveh through Professional Learning Community Assessment-Revised (PLCA-R) and TSES. Furthermore, qualitative data were collected via conducting individual semi-structured interviews with 10 teachers from public schools. Correlation analyses and multiple regression analyses indicated that professional learning community variables correlated significantly with Iranian EFL teachers' self-efficacy. Shared and Supportive Leadership and Shared Vision and Values appeared to be two components of effective PLCs which related significantly with Iranian EFL teachers' self-efficacy. These results prompted more examination of the particular characteristics and conditions which exit in PLCs that are associated with teachers' self-efficacy. Results of correlation analysis were further considered to recognize parts that needed more exploration. The findings of this study suggest that performing a shared leadership approach and a shared vision approach could increase Iranian EFL teachers' self-efficacy. Also, qualitative data reading teachers' perception of self-efficacy and professional learning communities revealed no strong categories. Additionally, the responses between teachers with high self-efficacy and teachers with low self-efficacy were highly reflective of each other, providing inconclusive results.
