ABSTRACT: Experiment 1 used the Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998) to measure self-esteem by assessing automatic associations of self with positive or negative valence. Confirmatory factor analysis (CFA) showed that two IAT measures defined a factor that was distinct from, but weakly correlated with, a factor defined by standard explicit (self-report) measures of self-esteem. Experiment 2 tested known-groups validity of two IAT gender self-concept measures. Compared with well-established explicit measures, the IAT measures revealed triple the difference in measured masculinity-femininity between men and women. Again, CFA revealed construct divergence between implicit and explicit measures. Experiment 3 assessed the self-esteem IAT's validity in predicting cognitive reactions to success and failure. High implicit self-esteem was associated in the predicted fashion with buffering against adverse effects of failure on two of four measures.