Hepatic infiltration in hairy cell leukemia is quite common but results of liver test are usually normal. A 44-year-old man with a history of alcohol abuse was evaluated for persistent elevation in serum aminotransferases. A percutaneous liver biopsy showed an extensive mononuclear cell infiltrate in the sinusoids and this finding led to the diagnosis of hairy cell leukemia. Liver involvement in hairy cell leukemia is discussed. Hairy cell leukemia should be considered as a potential cause of persistent increase in liver-related enzymes.