Menkes disease is an X-linked recessive copper transport disorder characterized by neurological deterioration, connective-tissue damage, and abnormal hair growth. It is caused by the mutation of the ATP7A gene. This report describes a four-month-old boy with neurological symptoms typical of Menkes disease plus unusual liver involvement. He developed seizures at three months of age and exhibited hypotonia, cephalhematoma, a sagging face, redundant and hypopigmented skin, and abnormal hair growth. In addition, he had unexplained hepatomegaly and high hepatic transaminase. We confirmed the diagnosis of Menkes disease by mutation analysis of the ATP7A gene. To exclude other possible causes for the hepatic abnormalities, a liver biopsy was performed, revealing intracytoplasmic cholestasis, focal spotty necrosis, and minimal lobular activity. The patient's liver involvement may be an underestimated complication of Menkes disease.