The principle of evidence-based decision-making for development policy and planning is now well accepted, and population data are of critical importance. Some ministries (eg., Health) are even including targets for program managers in the “use of reliable data in 75% of their decisions”. In 2008–2009, four African countries were selected for a study to assess the demand for, access to and use of demographic data for development decision making. In the Ethiopia case study presented here, the authors carried out nearly 100 key informant interviews of decision makers, key advisors, planners and media, at Federal and regional levels, plus follow up dialogue with selected and forthcoming policy advisors. The main finding is that demand for demographic data has increased, with the heightened need for monitoring international (eg, poverty, Cairo conference and MDG) targets and national results-based planning, as well as decentralized and locally empowered planning. However, there is still weak demand by international partners for developing strong and transparent national M&E systems. The demand and supply side barriers to effective use include: limited awareness of the value and type of data available; differing sources of information available on the same indicator (eg., contraceptive prevalence, ante-natal care) with contradictory estimates; old, unrepresentative and non-disaggregated data; research and survey findings not communicated well to policymakers, and skepticism and even mistrust of unexpected demographic statistics. Applied research, rigorous evaluation and data generation and analytical capacity in the country are weak, and the lack of demographic media expertise exacerbates the data use gap. The overall recommendation is advocacy for a culture of transparent information in order to rebuild trust and promote strategic use, as well as active involvement of the media to promote awareness of the importance of demographic data for development. Technical and institutional capacity building include the strengthening of key statistical, research and data collection institutions; improving true international partnerships towards increasing local ownership for large scale demographic data collection, research and M&E systems. It is also important to resolving key indicator contradictions between service statistics and household surveys through committed harmonization of sources, improve communications between data analysts, media and policymakers, and the creation of a well-functioning National Population Council. More research is needed on the socio-cultural and historical barriers to enabling a greater culture of reliable data.