A 70-year-old woman suffering from HCV-related liver cirrhosis was admitted for abnormal bleeding. Laboratory findings included PT at 46.6 sec, APTT at >212 sec, factor V activity of <3%, and factor V inhibitor of 2 BU. Having experienced a persistent bleeding tendency for one month, the patient was started on prednisolone (0.8 mg/kg/day). Within a few days, the inhibitor became undetectable and clinical bleeding disappeared. Although clinical improvement was achieved, she died 6 months after the initial bleeding episode from the progression of a lung cancer. An autopsy revealed squamous cell carcinoma of the lung and hepatocellular carcinoma.