This study is the largest meta-analysis to date of Black-White mean differences in work performance. The authors examined several moderators not addressed in previous research. Findings indicate that mean racial differences in performance favor Whites (d = 0.27). Effect sizes were most strongly moderated by criterion type and the cognitive loading of criteria, whereas data source and measurement level were influential moderators to a lesser extent. Greater mean differences were found for highly cognitively loaded criteria, data reported in unpublished sources, and for performance measures consisting of multiple item scales. On the basis of these findings, the authors hypothesize several potential determinants of mean racial differences in job performance.