Hexachlorobenzene (HCB) is widely distributed and has high persistence in the environment. In the 1970s restrictions on its use as a fungicide for cereal grains were initiated, but there are other uses and releases from chemical manufacturing industries and waste disposal operations. Representative values for HCB in environmental media and in man have been used in an exposure commitment assessment. The human body burden of HCB, estimated at 0.7 mg, is derived mainly from dietary intake of fatty foods, diet contributing approximately 0.2 microgram day-1. Inhalation is estimated to contribute about two orders of magnitude less. The assessment indicates a low exposure to HCB from the general environment, but populations exposed to direct contamination have had increased intake via one or both pathways.