Rrecent development of diffusion weighted imaging (DWI), is a MRI sequence make it possible image and evaluate the lesion in the lung. The aim of the present study was to differentiate benign and malignant lung lesions. A retrospective study conducted at the MRI units of oncology teaching hospital of medical city, Baghdad-Iraq in the period from March 2017 until January 2018, 33consecutive patients (18 males, 15 females) with variable lung lesions found on MRI. Mean age was 60.8 ± 14.5 years, with 18 males and 15 females, 75% of the lung lesions were malignant, DWI – MRI show 91.7% SN, 100% SP, 100% PPV, and 81.8% NPV for diagnosis of malignant lung lesions, ADC value were significantly lower in malignant lesions compared to benign lesion (1.08 ± 0.41 vs. 1.99 ± 0.42, p <0.001). ADV have excellent ability (AUC = 0.938) to discriminate malignant lesions with optimal cut point of ≤1.4. DWI – MRI both qualitatively and quantitatively (using the ADC value) is useful in the diagnosis and distinguish type of lung lesions.