Background: Children and young adolescents are reaching puberty earlier. Providing information about such changes before puberty can help them develop in a more competent and informed manner. Context and Objective: UNESCO's "International Technical Guidance on Sexuality Education" forms a comprehensive, evidence-based, authoritative document. This review analyses the Guidance for children and young adolescents aged 9-12 years who attend upper primary school. These students are very likely to be experiencing puberty, but are very unlikely, in many countries, to receive sufficient sexuality health information or education from parents or school at this crucial time. Design: This review analyses the text and narrative of this internationally-acknowledged sexuality education curriculum, and the relevant learning objectives/key ideas of a comparable state-designed health and physical education curriculum. Setting: Children and young adolescents who attend upper Primary school. Method: Analysis of text and narrative of this UNESCO Guidance. Results: Analysis shows that UNESCO's Guidance has greater, more relevant content, wider coverage, specific definitions and vocabulary, and more learning objectives, than does a contemporary upper primary school curriculum for the same cohort. Conclusion: Health curriculum designers and teachers can use this helpful Guidance to provide students with a fulsome puberty learning experience including age-appropriate knowledge, understanding, skills and values.