A gender perspective in disarmament and security affairs entails a conscious and open process of examining how women and men participate in and are affected by conflict differently. It requires ensuring that the perspectives, experiences and needs of both women and men are addressed and met through disarmament and peace-building activities and objectives. These are not abstract intellectual musings—they have real implications for the success and sustainability of peace and security. This issue of Disarmament Forum examines how gender relates to disarmament and security issues. Contributing authors explore gender aspects of early warning, the role of gender in DDR programmes, masculine behaviour and violence, and consider specific UN efforts concerning gender mainstreaming—including the Gender Action Plan of the Department for Disarmament Affairs.