The aim of this study was to investigate and compare prospective elementary and secondary school mathematics teachers’ opinions on proving. The work was implemented in a government university located in the western Turkey with 79 prospective secondary mathematics teachers enrolled to pedagogical education program of faculty of art and sciences and, 98 senior students of elementary mathematics education program enrolled to faculty of education. In the work, “Views on Proving Questionnaire” and demographical form were used. In order to analyze the obtained data, descriptive statistics and 2 (school) × 2 (gender) between-groups of analysis of variance (ANOVA) were used. According to results of the study, there was not a significant effect of the factors school and gender and interaction of school and gender on prospective mathematics teachers’ total scores of views of proving. However, there was a significant effect of factors school and gender and interaction of school and gender on total scores of the some subscales.