2,4,6-Trichlorophenol-14C was applied to soil (2 mg/kg fresh weight) in a closed aerated laboratory soil-plant system containing barley, carrot, cress, maize or beans, respectively. During 7 or 21 (for the carrots experiments) days, respectively, volatilization and mineralization, uptake by plants via roots and via leaves, and conversion to soil-bound and plant-bound residues were determined. Mineralization to 14CO2 within 7 days varied between 17 and 25%. More than four fifths of the radioactivity left in soil after 7 days was due to unextractable residues. Uptake of 14C into plants mostly was foliar uptake of 14CO2 from the air; bioaccumulation factors of root uptake were below 1 except for barley with a bioaccumulation factor of 2.5. Considerable portions of the radioactivity found in plants were due to unextractable residues.