This study aimed to identify the beliefs of preservice mathematics teachers receiving formation program as undergraduates or graduates in the Faculty of Science and Letters about teacher and student roles in the classroom setting and to explore how their beliefs changed at the end of the program. The research was conducted in the qualitative research design. The data were collected with a form of three open-ended questions asked to the preservice mathematics teacher attending the formation program in the faculty of education in the fall term of 2014-2015 academic year. The data were collected by applying this questionnaire to the preservice teachers at the beginning and end of the formation program. The answers of the preservice teachers were analyzed by classifying thematically by similarity and difference using the MAXQDA 11 qualitative data analysis software. While the preservice teachers had had beliefs placed somewhere between absolute knowing and transitional knowing about both teacher and student roles before the formation program, these beliefs were transformed into ones placed somewhere between transitional knowing and independent knowing after the formation program. This result indicated how important the pedagogical formation programs are for preservice teachers.