This WHO guideline provides comprehensive, evidence-based recommendations for the prevention, diagnosis, and treatment of infertility. It emphasizes equitable, person-centred, and accessible fertility care as an essential component of sexual and reproductive health. Developed through a multidisciplinary process using the best available scientific evidence, the guideline aims to support healthcare providers and policymakers in delivering safe, effective, and high-quality infertility services while promoting universal health coverage and reducing stigma and discrimination.