Wilson's disease is an autosomal recessive disorder. More than 60 mutations of the Wilson's disease gene have been described so far. We have analysed 148 Polish Wilson's disease patients from 95 families for His1069Gln and Gly1267Lys mutations and correlated this finding with age and clinical form of the disease at presentation. To identify these mutations, single strand conformation polymorphism analysis was performed. In our group there were 94 patients with neurological presentation, 28 with hepatic presentation, whilst 26 were in a pre-clinical stage of the disease. His1069Gln mutation was present on 171 (57%) of the 296 studied chromosomes, and Gly1267Lys mutation was present on 27 chromosomes (9.1%). Most of our patients were homozygous or heterozygous for His1069Gln mutation (39.9% and 30.4%, respectively); 4% of the patients were homozygous for Gly1267Lys mutation and 5.4% had both of these described mutations on their chromosomes. His1069Gln and Gly1267Lys mutations occurred often in our Wilson's disease patient population but we did not find any relationship between investigated mutations and the clinical form of Wilson's disease or age of first symptoms.