This Addendum updates the Global Counterterrorism Forum (GCTF) Good Practices on Women and Countering Violent Extremism (CVE) 1 to include a focus on mainstreaming gender, inter alia, based on new insights on gender-specific motivations and pathways of radicalization to violence and CVE responses that aim to counter women and girls’ recruitment specifically, while also addressing men and boys’ recruitment. It provides practical guidance to inform effective CVE policy and programming in light of the evolving roles of women in violent extremist and terrorist organizations, the diverse involvement of women and women’s organizations in preventing and responding to these challenges, and the impact of counterterrorism strategies on women’s human rights and women’s organizations. The Addendum draws from discussions with civil society organizations (CSOs), academics and governments at two consultative meetings, co-hosted by Australia and Indonesia as chairs of the GCTF CVE Working Group. These were a Workshop on Gender and Preventing/Countering Violent Extremism (P/CVE): the role of CSOs, 18-19 December 2018, Melbourne, Australia and a Workshop on the CVE Challenges of Returning Foreign Terrorist Fighters (FTFs) and their Families, 7-8 March, 2019 in The Hague, the Netherlands. The Addendum also complements and builds on the GCTF Good Practices on Addressing the Challenge of Returning Families of FTFs and The Hague-Marrakech Memorandum on Good Practices for a More Effective Response to the FTF Phenomenon and its Addendum with a focus on returning FTFs.