For the purpose of joint interests and promoting economic, social and cultural developments, the city of Karlovac may establish cooperation not only with local and regional governments within the Republic of Croatia, but also with local and regional governments of other states. The city of Karlovac today has established and maintained friendly relationships with many cities.
The first friendship was concluded in 1964 with the city of Alessandria (Italy), and has been maintained through economic and cultural cooperation and exchange. The help provided to Karlovac by the city of Alessandria was especially visible during the Croatian War of Independence, and in remembrance of that, since 2005 the bridge across river Kupa between Dubovec and Drežnik carries the name "City of Alessandria bridge"
Kansas City, KS, USA
Friendship between Kansas City, USA and Karlovac is tied in with emigrants from Karlovac which culminated in 1977, when official cooperation was instituted. Cooperation is maintained by mutual visits from government officials, businessmen and immigrants, as well as cultural, artistic and sports organizations.
Budapest – VII district Erzsebetvaros, Hungary
The city of Karlovac twinned with the Budapest local self-government of the VII district - Erzsebetvaros in 2008, for the purpose of exchanging experiences in management and development of the city and mutual assistance to establish economic, commercial, touristic, cultural and sporting relationships, as well as exchange of children and an array of other activities.
From 1968 to the Croatian War of Independence, Karlovac was twinned with the city of Kragujevac in Serbia, and cooperation was maintained as part of the traditional "Caravan of brotherhood and unity" manifestation.