The objective of the study is to analyse two variables which are the principals’ instructional leadership and their emotional intelligence which can predict the level of self - efficacy among teachers in full boarding schools in Perak. The quantitative survey design study used the survey questionnaire to collect data. The strongest dominant determinant to teachers’ self-efficacy is the dimension of self-management among the principals of the full boarding schools in Perak (β = .786, t = 4.307 dan p = .000). The t-test conducted showed that the dimension is significant at p<.05 with the R value of (R² = .618) indicating that the dimension of self-management contributes 61.8% towards teachers’ self-efficacy. The study provides important information and data related to the level of self-efficacy among teachers in the full boarding schools in Perak. This is because the study is a one-of-a-kind study that specifically evaluates the relationship between teachers’ level of self-efficacy and instructional leadership of principals and emotional intelligence of the principals. Therefore, this study will become an important guide for future studies aiming to explore the aspects of self-efficacy of teachers in boarding schools.