Social movement activists perform emotional labour that helps create and mobilise networks of collective action. The emotions of activism often contribute to social movements’ different organisational geographies. Two grassroots networks of human rights activists that originated in Argentina (the Madres de Plaza de Mayo and HIJOS) developed different emotional geographies over time. Both human rights movements were formed by relatives of victims of past human rights abuses and operated throughout Latin America and beyond. The movements incorporated activists and supporters who were linked by shared emotional bonds and by a common interpretation of the emotions of their activism. Activists in the two networks strategically deployed and framed the emotions of their activism in order to sustain it and to enhance possibilities for building broader networks of collective action. The comparison of these two human rights activist groups demonstrates that social movements’ organisational and geographic trajectories are often related to activists’ shared emotional connections and to the emotional labour that they perform through their networks.