This report examines how CSE equips adolescents with the relationship skills they need to learn and thrive. Drawing on mixed methods research from Argentina (Buenos Aires Province), Armenia, Lao People’s Democratic Republic, Namibia and Nigeria (Lagos State), it explores how national, school-based CSE programmes influence learners’ knowledge, communication and emotional well-being.The findings show that well-delivered CSE can strengthen parent-child communication, deepen empathy among peers, and help young people identify unhealthy patterns in romantic relationships. The report highlights CSE’s broader role in supporting safe, respectful and supportive interpersonal connections, which will also contribute to good health and well-being outcomes in the longer term.These insights guide ministries and partners in refining national programmes so every learner receives CSE that equips them to build healthy relationships throughout life.