In both political and business leadership, gender inequality is a topic of frequent discussion. When examining the literature, one can find a deluge of peer-reviewed articles linking gender differences to leadership. This makes a comprehensive review of the findings untenable. The present work, therefore, focuses instead on reviewing the results from two complementary methodological approaches: self-assessments and other-assessments. Self-assessments involve the administration of surveys and questionnaires to leaders, asking them to rate their own leadership preferences and self-efficacies. Other-assessments involve collecting data from subordinates, peers, and superiors. Surprisingly, both methods offer very similar conclusions about gender differences in leadership: women are generally perceived as being better leaders than men, especially for transformational purposes.