Abstract Aim of the work To assess the utility of hepatic ADC of diffusion weighted MRI in the diagnosis of liver fibrosis in chronic hepatitis C patients and to evaluate its relationship with both the stage of liver fibrosis and grade of necro-inflammation. Subjects and methods Forty patients with chronic viral hepatitis C and 30 healthy control group were examined by 1.5 T MRI scanner using DWI at b-values of 100, 400 and 800s/mm2. The mean ADC values of both patients and the control group were correlated to biopsy findings and graded according to METAVIR scoring system. Results The mean ADC values of the liver at all b-values were statistically significantly lower in the study group than those of the control group. A strong negative correlation was found between the mean ADC value and the stage of fibrosis. No significant correlation was found between the mean ADC value and the grade of necroinflammation. Conclusion The ADC value of diffusion weighted MRI can be used to distinguish between liver parenchyma of patients with chronic viral hepatitis C and healthy subjects and it is useful for estimation of the stage of liver fibrosis but not valuable in estimation of the grade of necro-inflammation.