This study was conducted to examine the effect of dietary sodium alginate and fish oil on bodily accumulated trichloroethylene (TCE), which has been widely used as a halogenated solvent and is me-tabolized at a high rate. Each of three groups of rats was fed on either of diets containing cellulose-soybean oil (control), Na-alginate-soybean oil or cellulose-fish oil for 3 wk, and thereafter given a single oral dose of TCE (100mg (0.76mmol)/rat). TCE levels in the blood were moni-tored for 10 h after the administration of TCE. The peak concentrations of TCE in the blood tended to be higher in the alginate and fish oil groups as compared with those in the cellulose-soybean oil group, but not to a significant extent. TCE concentrations in the liver, kidney, brain and the three fat tissues (epididymal, perirenal and subcutaneous) were significantly lower in the alginate and fish oil groups than in the cellu-lose-soybean oil group. Fat tissue weights were also lower in the alginate group and fish oil group. The hepatic drug metabolizing enzymes could not account for the remarkable decreases of residual TCE contents in the alginate and fish oil groups. These findings indicate that the metabolism and excretion of TCE might be accelerated in animals with reduced fat tissue mass.