Three patients with symptoms and signs of hepatolenticular degeneration (HLD) who developed serious renal side effects of D-penicillamine (DP) had their therapeutic schedule changed to zinc. Patient 1, a 55 year-old man had been well until 12 years old, when skeletal changes (osteomalacia) due to tubular renal disturbance began. His diagnosis of HLD had first been established at age of 32 when he presented with "wing-beat" tremor. He was then begun on DP and his neurological symptoms resolved within one year of initiating therapy but skeletal abnormalities remained unchanged as a sequel. During the next 22 years the patient was continued on DP therapy but with poor compliance. Then the reappearance of his neurological manifestations occurred several times. By the age of 53, after one year without therapy, his neurological status has worse. DP was reinstituted but some weeks later his renal laboratory parameters became severely affected. DP was discontinued and zinc sulfate (220 mg three times daily) was introduced. On this therapeutic regimen his renal laboratory parameters returned to previous level after one month. Within one year on this therapeutic regimen neurological manifestations were resolved. After 31 months on zinc treatment he remains neurologically asymptomatic and his renal function is satisfactory. Patient 2, a 41 year old woman had been her diagnosis of HLD at age of 20, when following the diagnosis of the disease in her old brother, she was found to have the laboratory features of HLD and bilateral Kayser-Fleischer rings. DP treatment was recommended at that time but she quit the follow-up. When she was 23, an esophageal variceal bleeding occurred.(ABSTRACT TRUNCATED AT 250 WORDS)