<p>The stereotype of math being male-typed prevails among most Western societies. This math-gender stereotype is associated with math-gender misconceptions, which are scientifically incorrect specific theories about girls’ math abilities (e.g., girls inherently think less systematically and thus have less math ability than boys). Teachers may contribute to the dissemination of the math-gender stereotype via their behaviors (e.g., choice of stereotypic learning materials). Here, we researched teachers’ awareness of such math-gender stereotype-reinforcing behaviors in scripted classroom videos in relation to what teachers answered in stereotype and misconception questionnaires. In an online experiment, we randomly assigned 278 teachers to videos with a female vs. male model teacher’s math-gender stereotype-reinforcing behaviors. We instructed participants to evaluate the model teacher’s teaching behaviors. Teachers were more aware of the male model teacher’s than of the female model teacher’s math-gender stereotype-reinforcing behaviors. If the model and observer genders aligned, awareness improved. Most importantly, participants who agreed less with math-gender misconceptions were more aware of math-gender stereotype-reinforcing behaviors. However, awareness was unrelated to holding the math-gender stereotype. Videos of model teacher behaviors, like those developed in this study, could also be a useful means to measure to train teachers’ awareness of relevant classroom behaviors.</p>