Over the next eight days, they will perform in Karlovac, Draganic, Duga Resa and Topusko.
The festival's director, Zeljko Stajcer, said 443 groups had applied to participate in the festival, all members of UNESCO's International Council of Organisations of Folklore Festivals.
To date, Karlovac has been host to more than 2,000 members of folklore groups from 35 countries from every continent, it was said.