Following the establishment of UN Women in 2010 and the appointment of Christine Lagarde to the position of International Monetary Fund Managing Director in 2011, it appears that today the United Nations (UN) takes gender equality seriously, even within its own leadership ranks. Yet, while research on Women in Politics has paid little attention to women in international organisations, research on leadership in international organisations ignores the question of gender. This is despite an inherent connection between women's political careers domestically and internationally. Evidence suggests that although women have broken through the glass ceiling in international organisations and thus gained access to what has been termed the “world's largest men's club”, women continue to be systematically constrained in a way that enables them to gain access to leadership positions only in specific ways and under specific circumstances. Analysing the role of quotas and the nature of organisations in enabling access through the “glass ceiling”, the limitations of “glass walls” that channel women into gender-specific portfolios, situational dimensions such organisational crisis and instability, and the role of kinship in facilitating access, this paper shows that despite its potential to model and incentivise gender equality, the UN merely replicates domestic patterns of gender inequality.