Whereas confrontations of racial bias prompt negative self-directed affect (e.g., guilt) and reduce bias, confrontations of gender bias are typically disregarded. We examined the effectiveness of an evidence-based confrontation in which participants received concrete evidence of their discriminatory gender-biased evaluations. Participants were confronted with evidence that they evaluated a female applicant for a lab manager position negatively, which would have resulted in her not being hired, and that their evaluations were more negative than an otherwise identical applicant who was male. Experiment 1 found that this confrontation activated greater guilt and, in turn, concern about expressing and regulating gender bias in the future (hereafter “future concern”), relative to participants who were confronted about gender bias but without concrete evidence of bias. Experiment 2 showed that confrontation with concrete evidence of gender bias activated guilt and future concern whether the bias was framed as viewing women as not belonging in science or as unintelligent. Experiment 3 showed that the positive effects of confronting gender bias with evidence were just as strong as a parallel confrontation of racial bias. Experiment 4 showed that the positive effects also held in a non-STEM domain, and that these effects were not dependent on the situational salience of norms opposing gender bias. Thus, a robust strategy for effective confrontation of gender bias was established. However, we discuss difficulties with implementing this strategy in many real world situations, along with implications for how best to curb gender bias through confrontation.