Researchers have obtained inconsistent results on the relationship between leader narcissism and leader effectiveness evaluations. Here we draw on social role theory and recent findings on prescriptive gender stereotypes to propose that leader's and follower's gender influence the degree to which narcissistic leaders are perceived as effective. Narcissistic female leaders lack stereotypically gender appropriate qualities (e.g. kindness) and demonstrate undesirable qualities associated with the other gender (e.g. arrogance). This combination is potentially threatening to the traditionally higher status of males, thus resulting in poor leader effectiveness ratings, especially by male subordinates. Conversely, we expect narcissism to be tolerated in male leaders. We find support for this idea in a study on 145 leader subordinate dyads. Female narcissistic leaders were seen as less effective than male narcissistic leaders. However, looking more closely, these lower ratings were only found when male subordinates served as raters. Specifically, male subordinates rated female narcissistic leaders lower while their effectiveness ratings of male leaders were not affected by narcissism. Female subordinates showed no gender bias in their effectiveness evaluations of narcissistic leaders. Thus, gender differences may be an important source of inconsistencies in evaluations of narcissistic leaders.