The friendship and cooperation protocol between the cities of Athens and Barcelona was signed on 16th February 1999 in Athens. This was a framework agreement in which an exchange of information and experiences was foreseen in questions of municipal administration related to the Olympic Games as well as the collaboration between both cities in fields of mutual interest.    

In recent years, the relations between both cities have strengthened, focused on a common strategy of hosting refugees.  The collaboration has been made evident in the initiative of Solidarity Cities of Eurocities, promoted by both cities so as to consolidate efforts and empower the cities to host refugees and migrants.