The authors present a simple liver biopsy protocol that is a reliable and cost-effective method of diagnosing hepatic Wilson's disease. Biopsy specimens are obtained in routine fashion, without the need for copper-free solutions or instruments. The samples are then embedded in paraffin, stained for copper and copper-associated protein, and studied by light microscopy. Subsequently, a sample of hepatic parenchyma is excised from the paraffin block for chemical quantitation of tissue copper. This combination of methods generally yields reliable results and allows confirmation of the diagnosis in cases of Wilson's disease in which special stains for copper are negative. In most instances, electron-microscopic studies are not necessary.