This case study analyses the advocacy efforts of two civil society organisations, INFANT and ONNAS, to introduce a law to end the use of physical and emotional violence against children and adolescents in Peru. It highlights the involvement of children and adolescents in the work of INFANT and ONNAS. Children’s involvement in the advocacy campaigns helped raise the profile of the issue in the media and in society more widely. The case study examines factors that contributed to the success of their advocacy efforts. The campaign’s focus on positive parenting strategies instead of punitive parenting approaches, and collaboration with politicians, journalists and artists, enabled their efforts. The case study also identifies barriers faced and the wider context in which their work took place. Finally, it considers the work that has been done by INFANT, ONNAS and other actors to support the effective implementation of the law.