This study aims to show to what extent the variables of reflective thinking, inquiry skill and mathematics teaching self-efficacy belief affect each other, to show their rates of explaining each other, and to show whether inquiry skill is a mediating variable in the relationship between reflective thinking and mathematics teaching self-efficacy belief. The data which were collected to test the hypotheses regarding the relationships to be shown were evaluated with structural equation modeling. A relational screening model was used in the research. The participants of the study were 304 prospective primary school teachers studying in their third and fourth years in the Basic Education Department of Education Faculties in two different state universities in Turkey. As data collection tools, the "Reflective Thinking Level Determination Scale", "Inquiry Skills Scale" and "Mathematics Teaching Efficacy Belief Instrument" were used. According to the results of the study, reflective thinking affects mathematics teaching self-efficacy belief positively and significantly and explains it significantly. Reflective thinking affects inquiry skills positively and significantly and explains it significantly. Inquiry skill affects mathematics teaching self-efficacy belief positively and significantly. Reflective thinking and inquiry skill together explain mathematics teaching self-efficacy belief highly and significantly. Inquiry skill has a partial mediating effect between reflective thinking and mathematics teaching self-efficacy belief.