The Organisation for Security and Cooperation in Europe (OSCE), the largest regional security organisation in the world, has in recent years experienced a process of ‘gendering’ its policies and practices. However, this process has led to somewhat limited results, and the achievements made even risk facing a backlash. Why has the gender agenda met so much resistance in the OSCE context? This policy brief outlines some of the political and institutional barriers to the implementation of gender policies in the OSCE, both internally and in the organisation’s external programmes and activities. It also highlights some institutional opportunities for the OSCE in this field.