This report provides key messages on the relationship between population dynamics and sustainable development. It was prepared in the lead-up to Rio+20, the United Nations Conference on Sustainable Development, following extensive consultations and collaborations with thirteen sister agencies, civil society organizations, academics and the private sector. It served as the basis for over a dozen briefings and consultations prior to Rio +20. In addition to informing the conference, the report includes important lessons for discussions of international development goals post-2015.