Schools are where education and training take place face to face with students and student behavior is shaped. For the teaching profession, the importance of pedagogical formation, general culture and special field knowledge, it is also important for teachers to have a personality and character that will be a good example for their students. The purpose of this research is to examine the relationship between unwanted student behaviors and personality types that branch teachers working in secondary education institutions encounter in the classroom. It is examined whether the teachers' personality types and the undesired student behaviors in the classroom differ according to the variables of age, marital status, branch, seniority, educational status, the type of school they work at, the status of being assigned to the institution they work with, and the type of faculty they graduated from. A total of 260 branch teachers, including 152 women and 108 men working in Çanakkale, participated in the study. In the research, socio-demographic form, 40-item Adjective Based Personality Test developed by Bacanlı, İlhan and Aslan (2009) to determine the personality traits of teachers, and a table prepared by Güven and Özdel (2016) to determine the opinions of teachers about misbehaviors in the classroom and coping with these behaviors have been used as data collection tools. The analysis of the data obtained in the research was carried out with the SPSS (21) statistical package program. It was concluded that there was a significant difference between the demographic characteristics of the teachers, their personality types and the undesirable student behaviors they encountered in the classroom, and that there was a significant relationship between the teachers' personality types and the undesirable behaviors they encountered in classroom management.