The aim of this study is to examine the relationship between the effective functioning of the bureaucratic school structure and the teacher leadership culture. The study was carried out with the sequential mixed model approach, which is one of the mixed method designs. A total of 492 teachers working in primary, secondary and high schools located in Beyoglu district of Istanbul province in the 2016-2017 academic year were included in the quantitative section of the study, and 20 teachers from the same district were included in the qualitative section. The "Effectiveness of the School Structure Scale" and the "Teacher Leadership Culture Scale" were used in collecting the quantitative data of the study. Descriptive analysis, correlation analysis and regression analysis were used in the analysis of quantitative data. In the qualitative section of the study, data were collected through semi-structured questions. The content analysis was used in their analysis. In the study, it was determined that the effectiveness of the bureaucratic structure of schools was at the moderate level and the schools' levels of having teacher leadership culture were above the moderate level. The quantitative results of the study showed that the effectiveness level of the bureaucratic school structure had positive and significant relationships with the dimensions of occupational cooperation, school administrator's support and supportive working environment, which are the dimensions of teacher leadership culture. It was observed that the effectiveness of the bureaucratic school structure explained the behavior of school administrator's support, the supportive working conditions and the occupational cooperation environment that are the dimensions of teacher leadership culture, by 43%, 26% and 9%, respectively. Based on the interviews held with the participants, it was revealed that teacher leadership behaviors could be developed by school principals' constructive and cooperative behaviors and the occupational, administrative and institutional supports, which will enable the roles of teachers. Furthermore, it was shown that culture in which teachers could exhibit leadership behaviors could be strengthened by the enabling structuring of the bureaucratic school structure.