A 2-year-old, castrated, male European Shorthair cat was presented with inappetence, vomiting, and fever. Ascites and an irregularly nodular liver were observed on laparotomy; in view of the poor prognosis, the animal was euthanatized. Histopathologic examination of the liver showed a chronic hepatitis with cirrhosis associated with massive accumulation of copper in hepatocytes and macrophages, particularly in the fibrotic areas between the regenerative nodules. Electron microscopy and energy-dispersive X-ray analysis revealed lysosomal accumulation of copper in the hepatocytes. Analytical determination showed very high copper concentrations in the liver. No evidence for increased dietary or environmental copper could be found. This and the pattern of hepatic copper storage, the associated inflammation and fibrosis, strongly suggest a primary copper storage disorder.