Abstract:In a phenomenon known as paradiplomacy, cities are playing an increasingly important role in international relations. Through paradiplomacy, cities are co-operating internationally with other cities, and city networks have become important spaces for sharing experiences of and best practices in local public policy. Moreover, security policy is a increasingly important part of local policy-making. In Latin America, the concept of citizen security, based on a democratic and human rights approach, has developed in response to the legacy of authoritarian regimes from the 1960s to the 1980s. This article examines how security policies have been disseminated, discussed and transferred through Mercocities, the main city network in South America.