ABSTRACT: In 2020, the State Geological Institute of Dionýz Štúr solved a task aimed at assessing the chemical status of geothermal groundwater bodies (GWBs). In geothermal groundwater bodies where geothermal water is extracted, the stability of the chemical composition for individual sources was evaluated in those indicators that characterize the chemical type of water (total dissolved solids, Ca2+, Mg2+, Na+, Cl­, HCO3-, SO42-). The temporal trend of concentrations of the mentioned indicators in individual sources of the geothermal body was also evaluated. The interquartile range (IQR) method was chosen for the evaluation of the chemical stability of the geothermal water, whereas 1.5 times the interquartile range was conventionally accepted to determine the outliers of the data set. If the values of the indicators were not between the lower and upper limits of the dispersion, an expert assessment was made to decide whether it is due to an anthropogenic influence or a natural phenomenon caused by e.g. water regime in the discharge area. All geothermal groundwater bodies evaluated in this way were evaluated as being in a good chemical status. In the case of no geothermal source in the geothermal groundwater body or if the geothermal water extraction from an existing source is not implemented, this groundwater body was evaluated also as being in a good chemical status. It is based on the assumption that where water is not withdrawn, its chemical status cannot be influenced. Representative chemical analyses were not available for 8 geothermal groundwater bodies (however, water is extracted), and therefore they were not evaluated from the point of view of the stability of the chemical composition.