Transitions to upper secondary education are crucial to understanding social inequalities. In most European countries, it is at this moment when students are separated into different tracks and faced with a ‘real choice’ in relation to their educational trajectory. Based on a qualitative driven approach with multiple research techniques, including documentary analysis, questionnaires and over 100 interviews with policymakers, teachers and young people in Barcelona and Madrid, this book offers a holistic account of upper secondary educational transitions in urban contexts. Contributors explore the political, institutional and subjective dimensions of these transitions and the multiple mechanisms of inequality that traverse them. Providing vital insights for policy and practice that are internationally relevant, this book will guarantee greater equity and social justice for young people regarding their educational trajectories and opportunities.