Abstract Background: Differentiation of benign from malignant thyroid nodules remains a challenge. Diffusion-weighted magnetic resonance imaging is a recent non-invasive imaging can differentiate between benign and malignant lesions. Aim of Study: Evaluate the efficacy of Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) in discrmination between benign and malignant thyroid nodules comparing the results of Apparent Diffusion Coefficient (ADC) value with histopathological results. Material and Methods: This case-control study included 30 patients with solitary (dominant solid or mixed solid and cystic) thyroid nodules on the basis of ultras ono graphic examination (US) and 10 persons with normal thyroid of matching age and sex. All were subjected to clinical assess-ment, radiological assessment included thyroid US, color Doppler examination and conventional non contrast MRI, DWI and ADC maps were obtained. ADC values of each nodule were correlated with histopathological results. Results: The cut-off value for the differentiation of benign from malignant thyroid nodules was 1.3 X l0–3mm2/s with mean of (1.39±0.11 X l0–3mm2/s) for benign nodules and (0.81±0.17 X l0–3mm2/s) for malignant ones with the sensi-tivity and specificity are 100% and 88.9% respectively. The overall accuracy is 95%. Conclusion: Preliminary results showed that DW-MRI provides very useful and promising imaging to evaluate the nature of a thyroid nodule and in discrmination between benign and malignant nodules.