Background (purpose) Since HCV, infection may lead to hepatocellular carcinoma (HCC) .we investigated if CYP24A1 gene hyper methylation involved in HCC and the relationship between CYP24A1 gene and HCC Methods:-Fifty patients were selected from Tropical Medicine department and outpatient’s clinic of Zagazig University Hospitals. The patients were classified into: 15 patients with chronic HCV patients with cirrhosis, 15 patients with chronic HCV without cirrhosis and 20 patients have HCC on top of HCV .All patients were subjected to proper history taking, full physical examination, laboratory investigations, abdominal U.S and triphasic helical CT as well as real time PCR for detection of hyper methylated CYP24A 1 Results:-The three groups were matched together as regards age and sex. There are a high statistically difference among the three studied groups regarding level of CYP24A1 ,which was higher among HCC group 14.62±7.74 and the lowest level was among HCV group without cirrhosis 5.3±3.46 (P value =0.000) CONCLUSION: CYP24A1 promoter methylation increase in HCC patient on top of HCV infection