Pentachlorophenol-14C was applied to soil (23 kg/ha), and rice plants were grown over two vegetation periods under flooded conditions. The uptake of radioactivity by plants was 12.9% in the first and 2.5% in the second year. Rice roots (first year) contained 0.14% of the applied radioactivity as free pentachlorophenol; 0.06% was conjugated pentachlorophenol, 0.43% free and conjugated lower chlorinated phenols, 0.07% anisoles, 0.01% dimethoxytetrachlorobenzenes, 0.03% 1,2-dihydroxy- and/or monohydroxymonomethoxytetrachlorobenzene, 0.48% polar nonhydrolyzable substances, and 3.95% unextractable residues. In the straw (first year), neither pentachlorophenol nor lower chlorinated phenols or anisoles were detected; the main metabolite (0.63%) was probably tetrachlorobenzoquinone. In the grains, low radioactive residues (0.12% of applied radioactivity or 4 ppm equivalent to pentachlorophenol) could not be identified. In the second year (pentachlorophenol residues in soil corresponding to ∼8.4 kg/ha), the portion of unextractable residues in the plants increased, and lower chlorinated conjugated phenols were identified.