ABSTRACT: There are hundreds of underground mines irregularly distributed in Slovakia and these are dependent on regional geological structure. Their regional effects are difficult to assess, and their impact on groundwater flow regime is currently only systematically measured by piezometric wells at 5 coal mines, This contribution offers a possible manner of evaluating regional mine drainage effects on groundwater circulation using indirect parameters. These include (1) mine water discharge measurement (2) an index defining mine drainage impact in hydrogeologic regions, (3) calculation of specific mine water discharge in hydrogeologic regions and (4) estimation of the portion of mine water discharge affecting natural groundwater resources in hydrogeologic regions. Hydrogeologic regions where mines exist in Slovakia were examined under this proposed assessment procedure, and classification in 5 classes of mine drainage impact on groundwater circulation was utilized.