In this article, we analyse the process of migration by applying a social network methodology. Using the personal network approach, we focus on a case study of the Brazil-US migration system to analyse the formation of the so-called “industry of illegal migration”. We suggest that in migration systems, brokerage evolves not only because of historical and cultural changes, but also because the changes emerge within a structured environment in which brokerage can thrive, and this, in turn, causes the social networks to support and produce specialized actors (individuals and organizations) embedded in the “right positions” of the social structure in the migration process. In this particular case study, we suggest that brokerage seems to take place through gender-oriented networks and the personal experience and structural power of returned migrants. These returned migrants usually have more varied social contacts and types of relationships from which they can obtain richer information about the migration system.