Teacher leadership has been gaining more significance in recent years since there is evidence that it has positive impact on all school outcomes. Therefore, researchers are actively investigating the antecedents of teacher leadership to contribute to teacher leadership in educational settings. The current study aims to test the impact of school culture, openness-to-authority, teacher self-efficacy and teacher expertise on teacher leadership, using a within-subjects experimental design. 91 teachers from various state and private schools participated in the study. Participants were presented with four pairs of scenarios (8 scenarios in total). Each pair (2 scenarios) assessed one of the four concepts on teacher leadership. In each pair, the high and low value of the related concept (e.g., high self-efficacy vs low self-efficacy) was manipulated. Participants were asked to report the probability of the teacher described in the scenarios to exercise leadership. A paired t-test was conducted to compare participants' ratings of each pair. The results showed a significant difference between the first measurement and the second measurement of each concept. This result demonstrates that all four concepts have an impact on teacher leadership. School leaders can develop these four concepts to enable teachers to exercise leadership.