This scientific report examines the development, implementation, and initial evaluation of a school-based intervention, „Together for Tolerance,“ which aims to promote norms of respect, equality, togetherness, and dialogue, thereby strengthening intergroup tolerance and cooperation in a school context. Given the increasing diversity in society and the associated challenges, it is critical to take preventive measures to reduce prejudice and discrimination, especially among young people. The study is based on the fundamental assumption that the potential long-term consequences of untreated prejudice can lead to serious social problems such as hate crimes and extremism.Together for Tolerance – Miteinander füreinander“ was conducted at schools in Lower Saxony, Germany. The final report was written in German.