Soil-inhabiting ligninolytic basidiomycetes, such as Stropharia rugosoannulata, play an important role in the transformation of soil organic matter, including the degradation of pollutants. Information on the mechanisms of degradation of xenobiotics by these fungi and their ligninolytic enzymes is still limited. The degradative activity of the soil-inhabiting basidiomycete S. rugosoannulata towards four-rings PAHs was revealed. Fluorene and 2-carboxybenzaldehyde have been identified as products of degradation of fluoranthene and pyrene. The laccase of S. rugosoannulata was isolated and characterized; its main catalytic properties are is similar to that of well-known fungal laccases. The laccase catalyzed oxidation of 2,7-diaminofluorene as model of PAHs that propose the participation of this enzyme in the initial attack of molecules of PAHs.