In this study, teacher teams and teacher leadership in various randomly selected schools in Istanbul were measured and the relationship between student achievement and teachers' team and leadership degrees were investigated. According to the results of the study, teamwork and leadership perceptions do not show statistically significant difference according to demographic characteristics (p> 0.05). In leadership practices, only internal leadership dimension showed statistically significant difference according to marital status (p <0.05). There was no statistically significant relationship between teamwork and leadership dimensions (p> 0.05). It was found that there was a statistically significant and positive relationship between school success and teamwork (r = 0,308; p <0,001) and external leadership (r = 0,256; p <0,001). The effect of teamwork on school achievement was higher. The results of the qualitative analysis revealed that teachers generally had a structure compatible with leadership and teamwork, but these concepts were not examined sufficiently.
Teacher Teams; Teacher Leadership; Student Success.