Background: Although in most cases, the diagnosis of MS remains a clinical, magnetic resonance imaging became a fundamental imaging technique for the investigation and monitoring patients with MS, as it allows the visualization of lesions in the brain and spinal cord and help in understanding and follow of the disease and it is widely used to confirm the clinical diagnosis. Aim of TheWork: To evaluation of asymptomatic or inactive multiple sclerosis plaques by using diffusion weighted imaging and ADC value. Patients and Methods: We evaluated prospectively 50 patients with known multiple sclerosis and fulfilled McDonald Criteria 2017. Patients of interest were recruited from the Neurology department in Al-Azhar University Hospitals during two years (May 2020 to May 2022). Clinical diagnosis was performed by an expert neurologist with 10 years of experience in treating MS.Results: Receiver operator characteristics (ROC) curves for ADC value x (10−3 mm2/s) as a predictor of activity of the M.S disease in enrolled patients. ADC value x (10−3 mm2/s) indices were significant predictors as denoted by the significantly large area under the curves (AUCs), there was used to define the best cut off value of ADC value x (10−3 mm2/s) which was ≥1.292, with sensitivity of 82.1% specificity of 82.6% positive predictive value of 85.2%, negative predictive value of 79.2%, diagnostic area under the curve of 0.828 with p-value <0.001. Conclusion: Measurement of ADC value should be done as a routine study with conventional MRI in MS patients.