A Saudi family with Wilson's disease (hepatolenticular degeneration) is described. The index case presented with anicteric hepatitis and hydrops of the gallbladder. Neurological involvement appeared later. The diagnosis of Wilson's disease was based on the presence of Kayser-Fleischer rings, a low serum ceruloplasmin level, and an elevated urinary copper concentration. Histological examination of the liver biopsy specimen revealed active cirrhosis. Acute hepatic failure developed during D-penicillamine therapy. Continuation of the drug at a lower dose, along with other supporitve measures, was successful in reversing this. After three years of therapy, the index patient's neurological signs disappeared, and liver function and gallbladder size and function returned to normal. Family screening revealed that three other siblings have the disease, and all have been treated with D-penicillamine. The parents are related but are asymptomatic. An unusual feature of the index case was the presence of a distended nonfunctioning gallbladder that reverted to normal with decoppering. Although D-penicillamine treatment possibly precipitated the acute hepatic failure, paradoxically it was also successful in treating it.