ABSTRACT: Groundwater pollution by nitrogen compounds, mainly nitrates becomes one of the most serious hydrogeochemical problems during the last decades. Statistical model based on descriptive statistics and regression analysis has been formed to give information on distribution pattern of nitrates in Slovakia. The developed model tries to estimate and assume a natural - preindustrial background concentration of nitrates in groundwater. Correlation between nitrate content and altitude of sampling locality is exhibited in the paper. Nitrate concentration in the source water (precipitation) and consequently biochemical processes in the soils predominantly control the nitrate distribution in mountainous areas. On the other hand, anthropogenic source of nitrate concentration dominates usually in the low land part of Slovakia (under the 250 m above see level).