The concentration of mercury was determined in samples of the lichen Hypogymnia physodes, the moss Pleurozium schreberi, and the soil humus collected in Polish and Czech Euroregions Praded and Glacensis. The sampling sites were located in Bory Stobrawskie, Bory Niemodlińskie and Kotlina Kłodzka in Poland, and in Jeseniki and Gory Orlickie in the Czech Republic. The mean concentrations of mercury accumulated in the lichen (0.129 mg g(-1)), in the moss (0.094 mg g(-1)) and in soil (0.286 mg g(-1)) were fairly close to the corresponding concentrations in other low-industrialized regions. The highest concentrations of mercury were observed in the lichen and the moss samples from Kotlina Kłodzka. The primary deposition of mercury was evaluated using the comparison factor, defined as the ratio of a difference between the concentrations of a bioavailable analyte in lichens and in mosses, to the arithmetic mean of these concentrations.