Ninety-five cases of hepatolenticular degeneration have been studied, focusing particularly the clinical and laboratory characterization of the disease. On the clinical viewpoint the variability of the starting symptoms and the frequency of the Kayser-Fleischer rings were analyzed. As regards the laboratory findings the ceruloplasmin, blood and urinary copper, and aminoaciduria levels have been evaluated, as well as the radiological and scintillographic study of joints and bones, cranial computerized tomography and liver biopsy. In 54.4% of the cases the opening clinical picture was neurological, in 31.1% hepatic, in 14.4% psychiatric, in 7.8% osteoarticular, in 2.2% ophtalmologic (Kayser-Fleischer rings), in 1.1% hematologic (hemolytic anemia), and in 1.1% cardiac. Kayser-Fleischer rings were present in 84 of the 92 cases in which they have been searched for (91.3%). Concerning the laboratory findings, hypoceruloplasminemia was found in 98.8% of the cases in which it was investigated, hyperaminoaciduria in 94.7%, hypocupremia in 87.0%, increased cupruresis in 78.2%, osteoporosis in 79.4%, scintillographic changes of the joints in 67.6%; the CT-scan, performed in 11 cases, showed low attenuation areas in the basal ganglia of 2 patients. The significance of the mentioned laboratory findings and the presence of the Kayser-Fleischer rings for the diagnosis of Wilson's disease is discussed.