Although much is known about personality and individuals' job performance, only a few studies have considered the effects of team-level personality on team performance. Existing research examining the effects of personality on team performance has found that, of the Big Five factors of personality, Conscientiousness is often the most important predictor. Accordingly, we investigated the criterion validity of lower-level Conscientiousness traits to determine whether any one trait is particularly predictive of team performance. In addition to Conscientiousness, we examined the criterion validity of the other Big Five personality factors. We found that Conscientiousness and its facets predicted team performance. Agreeableness, Extraversion and Neuroticism were not predictive of team performance, whereas Openness had a modest negative relation with team performance. Copyright © 2010 John Wiley & Sons, Ltd.