The purpose of this study was to examine how male and female leaders view their own effectiveness as compared to their objective performance. This study also examined sex and gender differences in subordinate's views of male and female leaders. Forty-two mixed-sex groups led by appointed male and female leaders were observed to assess objective and perceived leader effectiveness. Gender role of participants was assessed using the Bem Sex Role Inventory (BSRI). No sex or gender differences were found in objective leadership effectiveness. An unexpected finding was that male and female leaders perceived themselves accurately as leaders. Significant differences were found in the way male subordinates rated men and women leaders when taking into account gender role. Results indicated that the study of gender bias in leadership is complex and should be examined in conjunction with gender role. Social role theory helps to explain this bias.