BackgroundThe Chilean health system has undergone profound reforms since 1990, while going through many political upheavals, and faced demographic, health, and economic transformations. The full information requirements to develop an evidence-informed process implied the best possible use of available data, as well as efforts for improving the information systems.ObjectiveTo examine, from a historical perspective, the use of data during the health reforms undertaken in Chile since 1990, and to identify the factors that have determined its utilization and improvement.DesignA qualitative methodological approach was followed to review the case study of the Chilean experience with data on decision-making. We use as the primary source our first-hand experience as officials of the Ministry of Health (MOH) and the Ministry of Finance during the reform period considered. Second, a literature review was conducted, using documents from official sources, historical accounts, books, policy reports, and articles about the reform process, looking for the use of data.FindingsThe Chilean health care reform process was intensive in utilization and production of information. In this context, the MOH conducted several studies, from the burden of disease, efficacy of interventions, cost-effectiveness, out-of-pocket payments, and fiscal impact to social preferences, among others. Policy and prioritization frameworks developed by international agencies influenced the use of data and the studies’ agenda.ConclusionsHealth systems in Latin America have struggled to adapt to changing health needs caused by demographic transition and economic growth. Health reforms in Chile provide lessons of this sustained effort, based on data and scientific grounds, with lights and shadows. Tradition, receptiveness to foreign ideas, and benchmarking with international data determined this approach, facilitated by the political influence of physicians and other technocrats. Besides, internationally comparable statistics are shown to play a significant role in policy debate.