The Economic Community of West African States (ECOWAS) and its Member States are increasingly adopting policies and measures aiming at maximizing possible benefits of migration for development. This chapter analyses how ECOWAS Member States engage with their diasporas. It draws on an analysis of United Nations, African Union, ECOWAS and national policies, strategies and regulations on migration, diaspora and development. It finds that in ECOWAS Member States, policy attention to migration and the diaspora is recent, but rapidly increasing. Diaspora-related measures are integrated in the migration policies and strategies that have been/are being developed since 2014 in 14 out of 15 countries. In some cases, diaspora policies were adopted before wider migration policies. Whereas 13 out of 15 States mention diasporans as development actors, they define their possible contributions to development differently. They all mention financial transfers, whereas fewer States mention migrants’ skills and knowledge transfers, political influence transfers and benefits of diaspora political engagement. Diaspora institutions have been created in 13 countries, in 8 cases with a ministerial status. However, a scarcity of data on diasporas hinders effective policymaking.