TERCE is a large scale study of learning achievement, which was implemented in 2013. In total, 15 countries took part (Argentina, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru and Uruguay), as well as the Mexican state of Nuevo Leon (Mexico). This study assesses the performance of pupils in third and sixth grades primary school in mathematics, reading and writing, plus natural sciences in the case of sixth grade. Its main goal is to provide information for the discussion on education quality in the Region. It also aims to orient decision making in educational public policies. In order to achieve it the study involves the application not only of tests to measure learning achievements, but also of context questionnaires, to gain understanding of the context and of the circumstances in which learning occurs inside the areas being assessed. The first set of results consist of the presentation of comparative results between TERCE and the second study (SERCE, 2006) to measure learning achievements in primary education in the region. This comparison demonstrates the changes which have occurred in the performance of the educational systems of participating countries over the last seven years.