Purpose: Whilst professional learning communities (PLCs) have been widely explored at the school level, they have received less attention at the departmental level. The study takes the variance between departments and the role of departmental teacher leaders into consideration, and the relationships amongst departmental-level PLC dimensions, two types of teacher leadership (TL) and individual teacher self-efficacy are investigated. Design/methodology/approach: The sample consisted of 907 teachers from 81 departments in Chinese schools. The associations between the studied variables were explored through a multi-level analysis approach. Findings: The results show that two specific characteristics of departmental PLCs, namely reflective dialogue (RD) and collective responsibility (CR), exhibit a positive correlation with individual teacher self-efficacy. Additionally, the findings indicate that teacher transformational leadership significantly predicts teacher self-efficacy, whereas teacher instructional leadership (IL) does not emerge as a significant predictor. These findings may be attributed to the contextual factors of Chinese teachers' collective work and the practice of teacher leaders. Originality/value: This research contributes to the existing literature by addressing the variance between departments and uncovering the impacts of departmental PLC dimensions on individual teachers. Furthermore, two TL styles at the departmental level are differentiated, and their distinct influences on teacher self-efficacy are further analysed.