Background: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. Local ablative therapies include chemical (ethanol, acetic acid) or thermal ablation [radiofrequency ablation (RFA), microwave, laser, cryoablation] are curative treatment options that treat HCC. The apparent diffusion coefficient (ADC) calculated in diffusion-weighted MRI has become a favorable biomarker of tumor. The ADC is a measure of the mobility of water in tissues Methods: 30 cases of patients having HCC to radiology department of Damietta Cancer Center who underwent locoregional therapies (radio frequency ablation, microwave ablation percutaneous ethanol injection and trans-arterial hepatic chemoembolization) over a period of 18 months (APR.2017–OCT.2018). Patient are scheduled for dynamic contrast enhanced (DCE) MRI and diffusion weighted images (DWI) either in the routine follow up or after inconclusive triphasic CT study to assess tumor response to treatment and detect residual or recurrent lesions.  Results: The ADC variable was found to be a fair indicator to differentiate marginal recurrence of HCC from benign or pseudo- lesions the sensitivity of DWI was 80%, its Specificity was 76.7%, positive predictive value was 53.3% and negative predictive value was 92%. Conclusion: we concluded that DWI together with conventional imaging is a promising tool in the evaluation of HCC post ablation. DWI can provide information about molecular tissue characteristics; it can help to distinguish between viable and necrotic tumor areas thus facilitating the diagnosis of residual or recurrent tumor.  We could recommend a cut -off value 1.024 x 10-3mm²/sec, with t values below this level, express viability of the malignancy.