Purpose: Much of the literature on school leadership has concerned itself with the leadership practices of school principals, largely ignoring the leadership capacity of teachers. Much remains unexplored regarding the factors influencing teacher leadership, as well as the impact it has on teaching and learning. Addressing this gap in the literature, this study sought to investigate (1) whether teacher trust influences teacher leadership and (2) whether teacher leadership influences instructional practices directly or indirectly through teacher self-efficacy. Design/methodology/approach: The study employed a cross-sectional survey design using quantitative methods. A total of 618 teachers participated in the study. By performing structural equation modeling (SEM), we examined the direct and indirect effect of teacher leadership on instructional practice, with self-efficacy as the mediating variable while teacher trust was treated as the antecedent of teacher leadership. Findings: The results indicated that teacher trust had a direct effect on teacher leadership, and while teacher leadership had no direct effect on instructional practices, an indirect effect was evident through the mediating effect of teacher self-efficacy. Research limitations/implications: Our findings suggested that teacher leadership is a salient factor that influences teacher instructional practice by enhancing teachers' belief in their capability to cope with problems and improve student learning. Moreover, teacher trust provides intangible support for teachers to engage in leadership work. Since the current study employed a cross-sectional survey rather than a longitudinal one, we cannot accurately establish causal relationships among the study variables. Originality/value: This study adds nuance to the literature on teacher leadership, where there is still limited international evidence regarding the factors that influence the enactment of teacher leadership, as well as those that mediate its effects on teaching and learning.