The aim of this study is to examine mediation effect of leader-member exchange in relationship between organisational culture and teacher leadership in educational organisations. The sample of the study consists of 502 teachers working in primary and secondary schools in district of Gaziantep, Şahinbey in 2014-2015 academic year. Quantitative data of the study has been gathered through Organisational Culture Scale developed by Glaser, Zamanou and Hacker (1987), Teacher Leadership Scale developed by Beycioğlu (2009) and Leader-member Exchange Scale developed by Liden and Maslyn (1998). In the analysis of data, structural equation model, regression and correlation analyses have been used. The main results of the research are as follows: There is a high level relationship between organisational culture and teacher leadership leader-member exchange. There is a moderate, positive and significant relationship between - leader member exchange and teacher leadership. Organisational culture is a significant predictor of both teacher leadership and - leader member exchange. According to teachers perceptions, interaction of schools organisational culture and - leader member exchange is at moderate level. Teachers often demonstrate teacher leadership. Teachers leader-member exchange perceptions was found to be partial mediator role in the relationship between organizational culture and teacher leadership. As a result of interviews hold with teachers and school principals, it has been revealed that teachers are not participants in school decisions, teachers meetings hold at school are not effective and efficient, teachers are eager for professional development but in this respect, they are not given opportunity. By the way, it has been found out that relationship among teachers at school at a sufficient level and teachers are willing for institutional development.
Key words: Organizational Culture, Leader-Member Exchange, Teacher Leadership