This thesis focuses on the use of medicinal mineral waters and thermal waters in spas. The aim of this work is to bring the terminology used, the current status of the use of thermal waters in Spa and Balneology Centres in Slovakia, as well as the state abroad. The conclusion is directly paid to geothermal borehole G-4, situated in a recreation area of Kosice near the no longer existent Gajda’s baths, discusses its features and functionalities its use for recreational and therapeutic purposes.