The present Manual presents practical approaches and measures that can be put in place, particularly in the justice system and in collaboration with other sectors, to prevent child recruitment and exploitation by terrorist and violent extremist groups. Pursuing the common goal of preventing child recruitment by terrorist and violent extremist groups involves working together, not only within the justice system but also with other systems such as child protection, education and health, to design early interventions for children at risk and ensure that these children and their families receive the protection, assistance and support that they need.