It is unclear why the number of women in the fields of Science, Technology, Engineering, and Mathematics (STEM) is still small. In this review article, I focus on gender stereotypes (i.e., the belief that “women canʼt do math”) from a social psychological perspective. It has been reported that women and girls are influenced by negative stereotypes in experimental settings as well as in the real world. For example, researchers have found that negative stereotypes can undermine the performance of women in math exams. More recently, implicit stereotypes have been found to affect womenʼs math preferences either equally or even more than explicit stereotypes. How can we counteract the effects of negative stereotypes? Interventions, such as informing women that their math performances and career decisions are often unconsciously influenced by gender stereotypes, have been introduced based on accumulated knowledge of both gender and stereotypes. Having reviewed such literature, I conclude that psychologists in Japan should put more effort into conducting research on how to encourage women and girls to pursue their career plans, especially in the STEM field.