The professional character of mathematics teachers is influenced not only by their ability to manage learning but also by their beliefs about the subjects they teach. These beliefs include beliefs about the nature of mathematics (BNM), beliefs about mathematics learning (BTM), and beliefs about assessments (BAM). Together, these beliefs shape the professional character of teachers (CTP). Research indicates that BNM serves as a foundational aspect of teachers' beliefs in mathematics and significantly influences both BTM and BAM. However, there has been a lack of studies addressing how BNM affects CTP, either directly or indirectly, with BTM and BAM as mediators. This study investigates how BTM and BAM mediate the relationship between BNM and CTP. Data were collected from 160 elementary school teachers via an online questionnaire, and the relationships were analyzed using PLS-SEM methods. The findings revealed that BNM significantly affects CTP when mediated by both BTM and BAM simultaneously, while direct effects of BNM on CTP, and effects using either BTM or BAM alone, were not significant. These results indicate that focusing on both BTM and BAM is essential for enhancing the professional character of mathematics teachers. Educational institutions and teacher training centers should consider these mediators in curriculum development. Further research is recommended to explore these dynamics in greater depth, accounting for various teacher characteristics.