The aim of this study is to investigate pre-service mathematics teachers' beliefs towards mathematics and modelling in mathematical modelling processes. To achieve this aim, a phenomenology design was utilized. The study was conducted with 30 elementary level pre-service mathematics teachers receiving mathematical modelling courses. A semi-structured interview form was used to explore teachers' beliefs. At the end of the study, it was seen that mathematical modelling applications caused an increase of application-oriented beliefs. It was also observed that pre-service teachers who had schema and formalism-oriented beliefs evaluated mathematical modelling practices as time consuming and incomprehensible. Findings imply that modelling applications should be included in all levels of mathematics instructional curricula, in addition to the undergraduate curriculum.