This study examined how White participants completion of an implicit measure of racial attitudes might actually present a risk of confirming the stereotype that Whites are racially biased. To test this notion, White undergraduates in Experiment 1 completed an implicit measure of race-based associations (the race Implicit Association Task (IAT); Greenwald, McGhee, & Schwartz, 1998) after being told nothing about the measure (control), that the measure indicated "racial bias" (high threat), or that responses to the measure reflected knowledge of, but not personal belief in, racial stereotypes (no threat). Results showed that performance was worst (i.e., most confirming of implicit racial associations) in the high threat condition and best in the no threat condition. Even performance in the control condition showed evidence of stereotypic race-based associations, indicating that the absence of stereotype threat did not completely eliminate traditional racial associations. Experiment 2 replicated these effects, but also showed that they were moderated by individual differences in motivation to control prejudiced responses. Specifically, IAT scores indicating stereotypical associations were higher under stereotype threat to the degree that individuals were concerned about appearing unbiased. Experiment 3 had White students complete the IAT under threat or no threat, but half the students were first allowed to affirm their commitment to being non-racist. When allowed to self-affirm, threat had no effect on IAT scores. Without affirmation, however, IAT scores were higher under high threat than no threat. Only those individuals motivated to control prejudiced responses, but not allowed to affirm commitment to non-racism showed higher IAT scores under high threat compared with no threat. These data show that Whites who are threatened by the possibility of seeming racist produce elevated IAT scores, that Whites motivated to control prejudice are ironically particularly vulnerable to this stereotype threat effect, and that opportunities to affirm ones commitment to non-racism attenuate this effect.