A woman in her 50s underwent hepatectomy for type B cirrhosis and hepatocellular carcinoma. Approximately 15 months postoperatively, she developed anemia, decreased white blood cell count, and peripheral neuropathy. Her blood test showed low serum copper and high serum zinc levels, and it was determined that the patient had copper deficiency due to excess zinc, which was caused by the long-term zinc intake that was prescribed by another department postoperatively. In addition to drug discontinuation, copper supplementation with pure cocoa was administered; subsequently, blood cell counts recovered, and peripheral neuropathy improved. Although zinc replacement therapy is becoming common in patients with cirrhosis, zinc can induce copper deficiency if continuously taken in large doses. Hemopenia due to copper deficiency is frequently difficult to distinguish, and neuropathy may be irreversible. The need to measure serum copper during zinc administration should be communicated.