This study aims to determine the relationship between leadership styles of school principals and whistle blowing behaviors of teachers. The sample of this study, which is designed in the relational survey model, consists of 393 teachers working in primary, secondary and high schools in the province of Mugla. The data were collected through "School Principal Leadership Style Scale" and "Whistleblowing Scale." In data analysis, descriptive statistics and regression analysis were applied. According to the findings obtained from these data, it was identified that teachers preferred internal whistleblowing at the highest level whereas they opted for external whistleblowing behavior at the lowest level. Besides, according to teachers' opinions, it was asserted that at the very most level school principals demonstrated transformational leadership behaviors. In addition, it was also determined that there was a medium level of significant relationship between the leadership styles school principals demonstrated and whistle blowing behaviors of teachers. Moreover, it was stated that as long as school principals demonstrated transformational leadership behaviors, teachers mostly preferred the internal whistleblowing type of behavior. On the other hand, it was remarked that teachers opted for anonymous whistleblowing behaviors as long as school principals demonstrated laissez-faire leadership behaviors.