The 2011 Chilean student movement was one of the most massive and original processes of social mobilization in Latin America in the last decade. Led by university students, the movement challenged the longstanding free-market orientation of educational policies in Chile, demanding a more active role for the State in the regulation and supply of education. In this article, we study the main educational and social factors that explain the emergence of the movement. We draw upon social movement theory as an analytical framework and use newspaper articles as basic sources of data. Our research suggests that the simultaneous expansion and privatization of the Chilean education system provided students not only with mobilizing grievances (e.g., disparity in access and quality) but also with capabilities and resources (e.g., critical awareness and higher aspirations) to advance political mobilization. We also find that student organizations created effective frames to take advantage of the windows of opportunity opened in Chilean democracy. Implications for comparative international research on education reform and social movements are also discussed.