Abstract Background: The majority of the lesions that occur in the breast are benign, benign lesions of the breast are more frequent than malignant ones. It is important to recognize benign lesions and distinguish them from breast cancer. Breast cancer is most prevalent and is the leading cause of cancer related deaths among women worldwide. Aim of the Study: To investigate the role of MR diffusion – weighted images as a complementary tool in evaluation of probably benign (BI-RADS-3) and suspicious (BI-RADS-4) breast lesions and its contribution to patient management. Patients and Methods: The current study included 30 patients with BIRADS3 and 4 breast lesions detected by breast ultrasound and mammography; their mean age was 41 years (±8.42) (age range, 30-70 years). All patients presented with a breast lump, four patients presented with inflammatory manifestations (red with hot tender swollen breast). The study was conducted in Ain Shams University Hospital during the period from December 2019 to March 2021. Cases were referred from General Surgery Departments in Ain Shams University Hospital. The patients underwent full history taking and clinical examination followed by ultrasound and mam-mographic examination, those patients cases categorized on ultrasound and mammographic as BI-RADS 3 and 4 were selected for DCE-MRI examination. Results: In this study, it was found that for mass lesions type I curve was found in 10 pathologically proven benign lesions, type III curve was found in 11 pathologically proven malignant lesions compared to 2 pathologically proven benign lesions, and type II curve was present in 1 benign lesion compared to 8 malignant lesions. Our findings for mass lesions showed that malignancies exhibit lower mean ADC values compared with benign lesions. In our study we calculated the ADC value with high b-values (600 and 1500) to avoid the signal attenuation caused by perfusion effects at low b-values. Conclusion: Use of DWI as a diagnostic tool can increase the specificity of breast MR imaging and can reduce the number of false-positive results and associated unnecessary biopsies. In addition, DWI can be performed without signif-icantly increasing examination time.