A 33-year-old man with Wilson's disease developed hemoptysis and radiographic evidence of nodular pulmonary infiltrates. A premortem diagnosis of hepatocellular carcinoma was made on the basis of alpha-naphthylannidase stains of pulmonary tissue obtained by open lung biopsy. We review all previous cases of Wilson's disease with this unusual complication and discuss the role of copper in hepatic oncogenesis as well as the alpha-naphthylannidase stain for the diagnosis of hepatocellular carcinoma.