Worldwide, societal shifts and behavioural patterns exacerbated by unique developmental vulnerabilities create a confluence of factors that place today's adolescents at heightened risks for poor health outcomes. Country-level data show that continued investment in effective prevention and treatment strategies is essential to protect adolescents' sexual and reproductive health. Whereas strategies must be tailored to the developmental needs of this age group and their social contexts, effective approaches are multifaceted. All adolescents need access to quality youth-friendly services provided by clinicians trained to work with this population. Sex education programmes should offer accurate, comprehensive information while building skills for negotiating sexual behaviours. Girls and boys also need equal access to youth development programmes that connect them with supportive adults and with educational and economic opportunities. Although progress has been made since the 1994 International Conference on Population and Development, adolescents continue to be disproportionately burdened by threats to their sexual and reproductive health.