Based on a rigorous and current review of evidence on sexuality education programmes, this International Technical Guidance on Sexuality Education is aimed at education and health sector decision-makers and professionals. It has been produced to assist education, health and other relevant authorities in the development and implementation of school-based sexuality education programmes and materials. Volume I focuses on the rationale for sexuality education and provides sound technical advice on characteristics of effective programmes. A companion document, (Volume II ) focuses on the topics and learning objectives to be covered in a ‘basic minimum package’ on sexuality education for children and young people from 5 to 18+ years of age and includes a bibliography of useful resources. The International Technical Guidance is relevant not only to those countries most affected by HIV and AIDS, but also to those facing low prevalence and concentrated epidemics.