The tissue distribution and excretion of 14C-epichlorohydrin was studied in male and female rats following an oral dose of 10 mg/kg. Organs containing the highest concentrations of radioactive label per unit weight were the kidneys, liver, pancreas and spleen. With the exception of the pancreas, these are the same organs in which epichlorohydrin-induced pathologic changes were reported by a number of other investigators, indicating a direct correlation between tissue levels and target organ toxicity. The principal route of excretion was via the kidneys, 38-40% of the dose appearing in the urine during the 72 h study period. Fecal excretion was relatively insignificant, representing less than 4% of the administered dose. Of the administered dose, 18-21% appeared as 14CO2 in the expired air, the majority being excreted in the first 4 h, suggesting a rapid and extensive biotransformation of the compound.