The volume collects the scientific contributions of those who participated at the realization of the project "Hermes Linking network to fight sexual and gender stigma" co-financed by the European Community within the Daphne III Program and aimed at preventing different types of violence related to gender and sexual orientation (homophobia, transphobia, violence against women and homophobic bullying). This project was simultaneously carried out in Naples, Madrid and Dublin where partners worked on the implementation of a network between local NGOs, the realization of trainings addressed to first responders and prevention interventions for schools at risk. To offer a complete perspective on these themes, this volume includes many papers belonging to different scientific disciplines, such as psychology, sociology, political sciences and gender and queer studies.