Alterations in trace element concentrations may be observed in patients with chronic liver disease. Notably, selenium and zinc levels are reduced both in serum and in liver tissue of cirrhotic patients. Low selenium levels have been involved in the pathogenesis of liver damage as this element is important in controlling the levels of toxic oxygen radicals in the cells. Zinc deficiency has been involved in the pathogenesis of a number of clinical findings in chronic liver disease. These include the possible role of zinc deficiency in the pathogenesis of hepatic encephalopathy, by inducing alterations in urea metabolism. In CC14 cirrhotic rats oral zinc supplementation reduces ammonia levels and increases OCT activity in the liver. Oral zinc supplementation has been also proposed in the treatment of cirrhotic patients with chronic hepatic encephalopathy, the results however are not yet conclusive.