Several toxicological studies have shown that some rodents, due to their freding habits, easily accumulate high amounts of pollutants in relation to other mammal species. Their limited living space significantly reflects the contamination level of their biotope. The article presents the results of 142 rodent tissues biomonitoring from the area of mining dumps of various ages at the locality Banská Štiavnica (Central Slovak Neovolcanites). The investigation was realized in summer and in autumn. The contaminations of Fe, Mn, Cu, Zn, Pb, Cd and Bi were determined in liver, kidney and spleen tissues of three dominant rodents: Apodemus flavicollis, Micotus arvalis and Clethrinomys glareolus. There was discovered a close connection among heavy metal contents in the soils, food and organs of the small mammals in livers, spleen and kidneys. Apodemus flavicollis seems to be the most suitable species from the viewpoint of geotoxicity monitoring because of its number at all studied sites and because of notable differences between the pollution and control sites.