In the plant drug collected at different localities in Slovakia and Bohemia in the same vegetation period of one year, the content of Mn and Zn were determined. The AAS method was employed after mineralization of the drug by the dry method (without mineralizing additives) and subsequent dissolution of the ash in a HCl solution. The content of both metals in the samples substantially differed (Mn: 24.7–2095.5 mg/kg, Zn: 46.5–362.0 mg/kg of the dried drug). The content of the ash, which was within the limits of the standard, excludes excessive pollution by dust fall-out. The birch tree most probably absorbs and cumulates Mn and Zn from the soil.

        Key words: Folium betulae – different localities – Mn and Zn contents