During a period of 18 months three workers were admitted to hospital with jaundice that had developed two to four months after beginning work at a chemical plant. Liver biopsies showed severe centrilobular, haemorrhagic liver cell necrosis. The pathological changes resolved within six to 18 months. No damage to other organs was observed. The only worker who resumed work at the plant developed clinical and biochemical evidence of relapse of liver damage. Exposure to carbon disulphide, isopropanol, toluene, and acrylonitrile among others was shown, but liver damage may have been caused by a synergistic, hepatotoxic reaction mediated through the hepatic microsomal enzyme system. It was not possible to decide which chemical was responsible.