Abstract Comprehensive sex and reproductive health education is crucial for promoting overall health and wellbeing, as it plays a vital role in dispelling misinformation, fostering positive attitudes toward reproductive health, and empowering informed decision-making among young people. Despite its recognised importance by global entities such as the World Health Organisation (WHO) and the United Nations Educational, Scientific and Cultural Organisation (UNESCO), comprehensive sex and reproductive health education remains insufficient worldwide. This inadequacy is a multifaceted issue, stemming from various factors, including governmental policies, social norms, cultural beliefs, inadequate curriculum, and insufficient teacher training. Schools, as primary providers of reproductive health education, often prioritise pregnancy prevention over other important reproductive health topics, leading to significant gaps in students' knowledge, further prompting young individuals to seek supplementary knowledge from external sources, like the internet or social media. To address this disparity and to promote reproductive health awareness, the International Reproductive Health Education Collaboration (IRHEC) was established in 2019 and aims to provide educational resources for the public, teachers and health professionals. The IRHEC have created a teaching guide specifically for teachers to cover all aspects of reproductive health, to be used in schools globally. To develop this resource, it has been essential to determine what is taught in schools and the attitudes of teenagers to reproductive health education and family building. In the UK, we examined the curriculum in the four nations and huge gaps were identified in reproductive health education. Subsequently, a survey was conducted with 931, 16–18-year-olds in England and pupils were asked their views on their education, if they had been taught about a list of reproductive health topics in school and their attitudes to these topics. They reported that topics around pregnancy prevention were taught, such as contraception (90%), and sexually transmitted infections (90%) but key subjects such as fertility (30%) endometriosis (3%) and PCOS (2%) were not taught. This survey has been repeated in Belgium, Greece and Japan and similar patterns observed. Teenagers in the UK (21%) and Belgium (18%) rated their school sex and reproductive health education to be either poor or very poor compared to teenagers in Japan (3%). In the UK, Belgium, and Japan, young people have similar future parenthood intentions. Most young people in the UK (64%), Japan (60%), and Belgium (60%) want to have children in the future. A higher percentage of young people in Japan (70%) expressed a desire for two children compared to those in Belgium (60%), Greece (53%) and the UK (49%). To ensure comprehensive sex and reproductive health education, efforts must be tailored to the needs of each community and demographic. Collaboration among policymakers, educators, healthcare professionals, and communities is essential to enhance school curricula to include a broader spectrum of reproductive health topics and promote culturally sensitive educational approaches. By doing this, we can empower young people with the knowledge and skills necessary to navigate their reproductive health journey with confidence. There is an urgent need for a concerted action to bridge knowledge gaps and ensure that young people receive comprehensive sex and reproductive health education.