The article provides a global comparison of IB World Schools in the lusophone space, including countries in three different world regions, in response to a lack of research on international education in Portuguese-speaking countries. Following an introduction to the literature on this topic, focusing on a widely known typology of international schools, we present the first results of three case studies of the IB school field in the metropolitan regions of São Paulo, Lisbon and Maputo based on an analysis of school websites, databases and public documents. The study is based on a global comparative approach that enables an analysis of the complex interrelation between global and local actors in education, primarily addressing the school level. We aim to provide some insights on the implementation and development of the IB World Schools in Portuguese-speaking countries, in the light of existing studies on international schools.