Adult female rats were given a single oral dose of hexachlorobenzene (HCB) (100 mg/kg, 1% carboxy methyl cellulose) by stomach tube. Six days after HCB dosage the diet of the animals was restricted to 30% of their normal intakes for 7 days. Following dosage and during partial starvation faecal elimination of HCB was monitored. The animals were killed on day 13 and their tissues removed for HCB analysis. A significant increase in HCB was found in all tissues, notably in the brain (367%) and the liver (496%), with HCB being mobilized from fat depots to plasma and then redistributed. The pattern of HCB faecal elimination suggests that food restriction enhances non-biliary excretion, correlating with plasma levels and faecal volume.