ABSTRACT: The presented paper gives brief information about the results of three geothermal wells - vertical GTD-1 and directional GTD-2,3 - drilled in Ďurkov geothermal structure. The main source of geothermal watcr occur in the upper part of Mesozoic dolomites in the depth about 2100 - 2500 m. Geothermal water from GTD-1 discharging with average free flow flowrate of 56 l.s-1 with temperature 125°C, dynamic pressure 0,92 MPa had 30 g.l-1 TDS. Geothermal water from GTD-2 discharging with average free flow flowrate of 70 l.s-1 with temperature 124°C, dynamic pressure 0,2 MPa had 28 g.l-1 TDS. Geothermal water from GTD-3 discharging with average free flow flowrate of 65 l.s-1 with temperature 123°C, dynamic pressure 2,20 MPa had TDS 31 g.l-1. Chemical character of water is remarkable natrium chloride type. Model calcium-carbonate equilibria calculations as well as measurements in situ suggest that the water has scaling and corrosion properties according to the pressure and temperature changes during utilisation in heat system.