It is expected that teachers encounter to undesirable student behaviors in the class. The reason of these behaviours is the students’ problem in their private life. Especially, schools in Istanbul have students with very different cultures. For this reason, the undesirable student behaviors encountered in these schools are also quite diverse. The purpose of the research is to investigate what strategies to cope with these behaviors are, and to find suggestions for an effective classroom management. The study group of the researchers cwas consisted of the teachers working in Esenler in the academic year of 2015-2016. Convenient sampling method was used in the research. The data of the study were obtained with the questionnaire "Teachers' Undesirable Student Behaviors and Coping Strategies with These Behaviors". 103 teachers participated in the survey. The obtained data were analyzed using SPSS 22 and the results were presented as frequency and percentage. As a result, t was determined that most the frequently used strategies were verbal warning and behavior modification.