Abstract Increasing number of studies have revealed that teacher's math anxiety is related to the use of less effective pedagogical practices, which can lead to reduced math achievement among elementary school students. Children's math experience begins before formal schooling. However, there is limited information about the effect of preschool teachers' math anxiety on math‐related activities. In the current study, 209 in‐service preschool teachers were recruited to explore the relationship between math anxiety and their involvement in math activities within the classroom. Our findings showed that preschool teachers with high levels of math anxiety reported feeling less comfortable teaching math, leading to reduced engagement in math‐related activities and decreased interactions with their students. Building upon these insights, potential strategies are proposed to mitigate adverse effects of math anxiety among preschool teachers and cultivate a more positive learning environment for children.