After a review of the fundamental steps in the history of hepatolenticular degeneration, the authors report 3 cases of the disease. Two patients died, the post-mortem examination having confirmed the clinical and laboratorial diagnosis. Among the neurologic particularities the presence, in one case, of flexion spasticity and cerebellar signs, besides the usual picture of Wilson's disease, is stressed. The Kayser-Fleischer corneal ring was always complete and bilateral. Among the unsteady features of the proteinogram of the cerebrospinal fluid, absence of pre-albumin, and lowering of 1 and 2 globulins were more frequently found. Low blood phosphorus and magnesium contents were found in our cases, seemingly for the first time in the literature. Special attention was dedicated to the study of liver and kidney functions through the proper functional tests. The impairment of liver function was mild, in a striking disagreement with the degree of the histologic picture of post-necrotic cirrhosis. Regarding the kidney, in two cases increased urinary excretion of aminoacids was found, associated with a slightly lowered tubular excretion in one of them. The genetic study could be more detailed in one of the cases, and included the search for Kayser-Fleischer corneal ring, the determination of copper in blood and urine, and of blood ceruloplasmin in the relatives, besides the cytogenetic study of the patient. Kayser-Fleischer ring was found in an otherwise asymptomatic sister, and disorders of copper metabolism were evidenced in her and some other relatives. The study of copper contents in the tissues confirmed the data of the literature regarding the overload in pancreas, kidneys, adrenal glands, liver, white and gray matter of the brain, thalamus, cerebellar cortex, and in the lenticular and caudate nuclei, as well as normal levels in the nails and low contents in the hairs. Presumably for the first time, an increase of copper concentration in the substantia nigra and red nucleus, as well as in the submaxillary gland and cerumen, was found. In the cerebrospinal fluid the total copper content was very close to the direct reacting copper level, and fell into the normal range. In bile our data agree with the references in the literature, the copper content being normal in total bile and in B-fraction, and low in A and C-bile. Low blood copper and ceruloplasmin contents and increased copper concentration in urine and saliva were found in the three cases. Blood direct reacting copper was determined only in one case and showed a moderate increase. The study of the metabolic balance showed a positive result for copper in the control periods, and a slight negative result for phosphorus. After the use of BAL, and especially of D-penicillamine, the copper balance became negative and the phosphorus balance turned out markedly negative. Low copper diet, cation exchanging resins or potassium sulphide were associated with the metal binding agents in different therapeutic schemes. The clinical improvement, although noticeable in case 3 after the use of D-penicillamine and estrogens, did not agree with the gratifying biochemical results.