The purpose of this study is to determine the relationship between teacher-parent cooperation and primary school students' undesirable behaviors in the classroom.The target population of the study in which relational scanning method is used includes the primary schools in Zeytinburnu county of İstanbul province in 2012-2013 academic year. 400 parents who were selected randomly from 5 schools were surveyed. The data of study were obtained by using a personal information form, "Parent-School Communication Attitude Scale" and "Parent-Teacher Communication Attitude Scale to Prevent Students' Undesirable Behaviors in the Classroom" were developed by Ergen (2008). The data obtained were analyzed through the SPSS17 programme. The following results have been found at the end of the study: Teacher-parent communication and primary school students' undesirable behaviors in the classroom have positive relationship. Parents' parent-school communication attitude do not differ according to the educational status, the number of people working at their home, ages, jobs, gender of children, children's class and their chilren's teachers gender but attitude differ according to parents' gender and their number of children. Parent-teacher communication attitude to prevent students' undesirable behaviors in the classroom do not differ according to parents' gender and jobs but attitude differ according to parents' ages, educational status, the number of people working at their home, the number of their children and children's class