The aim of this study is to identify the effect of the program which is developed for equipping the classroom teachers with the tasks and responsibilities of the mentor teacher. The current study examines the classroom teachers' opinions about the program who are enrolled in Mentor Teacher Training Program (MTTP) and the effect of the program on the classroom teacher candidates' opinions about the fulfillment levels of the tasks and responsibilities of the mentor teachers. The study has been designed as a case study. The study group consists of mentor teachers and classroom pre-service teachers. At the end of the study, it is found that mentor teachers regarded the MTTP beneficial for them and they said MTTP that need to be improved. At the end of eight months of work, the gathered conclusions showed the effects of being an aware mentor teacher. It has been found that there are fewer problems between the pre-service teachers and the mentor teachers participating in the MTTP. In line with the suggestions of the participant teachers, the practicum dimension of the teacher training can be more productive by re-arranging and disseminating the program. This research is a guide for developing a mentor teacher training program.