Since the 1990s, Chile has participated in all major international large-scale assessment studies (ILSAs) of the IEA and OECD, as well as the regional ones conducted by UNESCO in Latin America, after it had been involved in the very first international Science Study in 1970-1971. This article examines the various ways in which these studies have impacted on educational policies in Chile. It discusses how results were used for leverage purposes in law-making, and how the concepts and frameworks of specific ILSAs were integrated into crucial normative policy instruments, particularly curriculum standards, as well as the national assessment framework and instruments. In identifying main features and means of impact, the article illustrates that the use of data and criteria from international assessments varies in ambits and depth of impact, according to the larger features of the political context in which educational policies are embedded.