ABSTRACT A growing literature on stereotype validation suggests that negative, self-relevant stereotypes activated after poor task performance may lead stigmatized individuals to feel more certain they performed poorly. The present research examined a potential moderator of these effects: lay theories of intelligence. In two studies, gender stereotype accessibility was manipulated after participants finished a test of sports (Study 1) or science (Study 2) knowledge. Findings were consistent with increased stereotype validation among women who held incremental theories of intelligence. In particular, these women expressed elevated certainty in their poor performance when negative stereotypes were made salient after the performance. Furthermore, this enhanced certainty predicted negative downstream consequences for follow-up performance in the domain.