Net migration to OECD countries has tripled since 1960. As an immediate policy challenge, the integration of immigrants into labour markets has become a high priority and a research topic. However, very little research has focused on the integration of immigrant children into school. The OECD policy review of migrant education was launched to compare education outcomes of immigrant students to those of their native peers and, where gaps exist, to determine what actions policy makers could take to close the gaps. This introduction provides an overview of the project and introduces cross-cutting policy issues. It first explains why the OECD launched the policy review of migrant education. It then introduces eight government tools that are often in use for steering migrant education policy. They are: 1) setting explicit policy goals for immigrant students within broader education policy goals; 2) setting regulations and legislation; 3) designing effective funding strategies; 4) establishing standards, qualifications and qualifications framework; 5) establishing curricula, guidelines and pedagogy; 6) building capacity (especially training and teacher support); 7) raising awareness, communication and dissemination; and 8) monitoring, research, evaluation and feedback. It also presents the key cross-cutting, general messages, which will set the scene for Chapters 2, 3 and 4. The messages highlight: the importance of paying attention to “heterogeneity” among immigrant students; the significance of a holistic approach and shared responsibility at all levels and among all key stakeholders; and the challenge of finding the right balance between universal measures for all students and targeted measures for immigrant students.