This study investigated the moderating role of implicit stereotype endorsement on stereotype threat. In the experiment, female undergraduates completed a math test that was described as either diagnostic (stereotype threat) or nondiagnostic (control) of mathematical ability. After finishing the task, they completed implicit measures (see Greenwald et al., 1998) of gender stereotyping (i.e., stronger male-math than female-math associations), gender identification (i.e., stronger self-female than self-male associations), and math identification (i.e., stronger self-math than other-math associations), and an explicit measure of math-gender stereotyping. Math performance was lower in the threat compared with the control condition, but math performance was also moderated by implicit gender stereotyping. In the control condition, stronger implicit gender-math stereotypes predicted lower math scores. In the stereotype threat condition, implicit gender stereotyping was unrelated to math performance. There were no significant effects associated with implicit gender or implicit math identification or explicit math-gender stereotyping. These data suggest that women with stronger implicit stereotypes linking men with mathematics are more susceptible to the negative consequences of stereotypes, even in conditions that typically do not give rise to stereotype threat.