The present research tested relations between extraversion and emergent leadership among men in situations that differed in potential reward availability. Four-person groups of men engaged in a Leaderless Group Discussion (LGD) task and were randomly assigned to be evaluated by an attractive female observer, an attractive male observer, or not be evaluated. Evolutionary theories suggest that impressing a female evaluator in an intrasexually competitive situation should hold greater reward potential for men than impressing either a male evaluator or no evaluator. Accordingly, more extraverted men (who are more sensitive to reward cues) should display more group leadership when being evaluated by a woman than either a man or no one. Self-and peer ratings confirmed that more extraverted men were significantly more likely to emerge as leaders, but only in the female-evaluator condition. The results are discussed in terms of the interplay between personality, situational factors, and evolutionary principles.