The paper analyzes the Karlovac rivers as one of the main foundations of tourism development in the city of Karlovac. Karlovac is one of the few cities that within their administrative boundaries have four major rivers (in relation to the size of the city). Rivers Korana, Kupa, Mrežnica and Dobra provide a number of opportunities for the development of tourism with particular emphasis on vacation, sports, recreation, active holidays or just swimming. Rivers are the basis for the development of bathing tourism, rafting, paddling and many other sports and recreational forms of tourism The main objective which should be set in Karlovac is creating better use of tourism resources so that they can reach the largest number of tourists. It is necessary to keep in mind that tourism development enriches and improves the quality of life of local residents. If specific forms of tourism are used well, they may, among other things, improve the quality of tourist offer, extend the season beyond the summer months and lay the foundations for further development of tourist destinations.