Abstract Background: Lung malignancy is the most common cause of death in the developed countries. Male to female ratio is 3:1. Consumption of Tobacco upsurges the rate of evolving lung cancer by 30 folds. Other risk factors include repeated exposure to aspects like carcinogens, asbestos, pulmonary fibrosis and radiotherapy. Aim of Study: The aim of this study is to assess the role of diffusion weighted magnetic resonance imaging in charac-terization of pulmonary masses. Patients and Methods: This study was carried out on forty (40) patients 8 females and 32 males who had Pulmonary mass on the X-ray or CT chest and aged above 18 years old. All the studied patients underwent to detailed history taking, laboratory studies and radiological examination using MRI (GE 1.5 Tesla) using body phased-array Coil and DWI (b-value 0, 500, and 800s/mm2). Results: Thirty lesions were malignant, and 10 lesions were benign. The malignant masses showed significantly higher signal intensity on DWI than benign masses (p<0.001), and the mean ADC value of malignant lesions was significantly lower than that of benign lesions (p<0.001). By ROC curve, an ADC cut-off value of 1.6 X 10–3mm2/s was considered the threshold value, and the sensitivity and specificity were 100% and 90% respectively. Conclusion: Diffusion-weighted MRI and ADC can sig-nificantly differentiate between benign and malignant pulmo-nary masses.