The purpose of the two-teacher primary teaching model is to find a solution, to some extent, for the crowded classes and the classes in which the inclusive students study in primary school. Furthermore, it is aimed to increase the efficiency of the lessons, better take care of the inclusive students, implement the constructivist approach as required, collect the attention of the students who lost their attentions, support students who have difficulties in their studies, ensure that students who learn slowly can learn the lessons completely and increase the quality of education by giving additional studies to the students who learn quickly. The co-teaching model that can be considered as an alternative in solution of the educational problems can be used effectively in the crowded classes and the classes in which the inclusive students study. Moreover, this study can be considered as an alternative model so that the "Teaching Practice" lessons taken by the teacher candidates studying at the education faculty can be more qualified and efficient.The purpose of this study is to review the effectiveness of teaching practice in primary school based on co-teaching model. In this context, it was tried to determine the opinions of primary school teachers about the co-teaching model. To achieve this purpose, 12 primary teachers serving in the city center of Muş were determined as working group. In the study, the data were obtained by semi-structured interview method. Content analysis was used for the analysis of the data.According to the teachers' opinions obtained as a result of the study, the most important one of the problems experienced by the teachers during the teaching period is the crowded classes. It is concluded that in the crowded classes, the activities are not implemented at the desired level, it is not possible to allocate enough time for the students, incorrect and incomplete learning of students cannot be realized on time and it is difficult to give a student-centered education.As a result of the study, in order to ensure that the teaching practice can be efficient, it is concluded that the internship duration should be extended, the teacher candidates should be assigned more responsibilities, the teacher candidates should do internships in the rural schools and combined classes so that they can see different environments and they should carry out implementation-oriented studies rather than observation-oriented studies in this lesson.According to the teachers' opinions obtained as a result of the study, it is concluded that the co-teaching model will increase the efficiency of the lesson, the classroom management will be easier, this model will ensure that the students who fall behind and learn slowly can learn the lessons completely, the saving on time will be ensured, the opportunity to take care of students personally will increase, the workload of the teachers will decrease, the equal opportunity in education will be ensured by taking care of the inclusive students more than before and the faster and more practical solutions will be created for the problems to be encountered in the teaching process.