ABSTRACT: Long-term groundwater runoff assessment is based on the data available from the surface stream discharges (1971-1980; 1981-2005) of the 33 gauging stations in relevant catchments. The selected catchments evenly cover the whole territory of Slovakia. The catchments differ in parameters of the catchment size, altitude, climatic, geological, and hydrogeological conditions. The original Kille’s method and BFI model were used to ensure the results comparability within the whole territory of Slovakia.