The classroom is an active interaction and communication environment in which students are prepared for academic and socio- cultural life. The behaviors of classroom teachers, who are one of the most important actors of this environment as role models, are of great importance both for the students and the prospective teachers coming to gain experience in these classes. However, it is difficult to assert that teachers always exhibit only desirable behaviors in the classroom. This study aims to determine undesired teacher behaviors from preservice teachers’ points of view. The study was designed as a qualitative study and 21 preservice teachers who had attended the courses in school experience and teaching practice were the participants. The data were collected from focus group interviews with the participants using semi-structured interview forms. The interviews were recorded with the permission of the participants. The records were transcribed and these transcriptions were analyzed using content analysis. In the study, the results of the undesired behaviors of classroom teachers were presented under the basic dimensions of classroom management, communication, teaching, and guidance, and are discussed based on literature.