Biotransformation of the insecticide lindane was investigated in sterilized and non-sterilized soils, each supplemented or not by the white rot basidiomycete Phanerochaete chrysosporiurn. After spore inoculation of the sterilized soil, the fungal biomass increased rapidly during the first week, then proceeded at a lower rate during the following 8-wk. Conversely, only limited fungal growth was detected in non-sterile soils. Lindane mineralization, as a result of indigenous microflora activity, was increased following fungal inoculation. Then, extractable amounts of lindane were quite similar in soils, with or without fungal addition. Mass-balance and SPME analysis revealed the volatilization of degradation intermediates only from non-sterilized and non-inoculated soil. P. chrysosporium seemed to modify lindane degradation pathway by increasing the conversion of volatile intermediates to CO?.