Many studies have been conducted that emphasize the positive aspects of the cooperative learning method. The success of the cooperative learning environment depends on a well-organized learning environment. The most important element of this learning environment is teachers. The success of teachers in cooperative learning practices depends on the education they receive, the school environment, the way the administrator perceives the future, and the positive contributions of the students' parents.  It is very important to determine what kind of problems teachers experience while carrying out the collaborative learning process. The qualitative research method was used to determine the problems faced by high school teachers in the cooperative learning process. Phenomenology design, one of the qualitative research designs, was used in the research.  The study group of the research consisted of 32 teachers working in the Bornova district of İzmir province. The maximum variation sampling method, one of the purposive sampling methods, was used to determine the study group. As a result of examining the related studies in the literature for data collection, the researcher applied a semi-structured interview form consisting of open-ended questions.  53% (20) of the teachers participating in the study were female and 47% (18) were male. The rate of postgraduate education in teachers is gradually increasing.

As a result of the research, the participants mostly stated that they experienced various problems while applying cooperative learning in their lessons. The teachers, whose opinions we consulted, stated that school principals do not have enough knowledge about cooperative learning, that administrators are reluctant to create a cooperative climate, that teachers have difficulties in creating cooperative learning environments, that parents criticize themselves about cooperative learning activities, that students perceive cooperative learning activities as games, that students perceive activities in the classroom. They stated that they could not establish a connection between the central exams and the central exams and that they had various problems arising from the parents.

Keywords: Cooperative Learning, Education, Teacher, Manager, Self-Assessment, Learning Environment