Objective: To evaluate the role of MRI in differentiation of benign from malignant breast lesions using dynamic contrast enhanced MRI (DCE-MRI) and diffusion weighted MRI (DW-MRI).Patients and methods: The study included 33 female patients with clinically suspicious breast lesions detected by mammography and/or breast ultrasound. Cases were referred from general surgery departments in Tanta university hospital. The patients underwent full history taking and clinical examination, full field digital mammography and US, for those patients cases diagnosed on sonomammography as BI-RADS 3 & 4 were selected for MRI examination. Results: Quantitative analysis of DWI was done for the 33 breast lesions and their ADC values are recorded at 3 different b-values (250, 600, and 1000). Seventeen lesions showed facilitated diffusion, proved to be benign and 10 lesions showed restricted diffusion, 9 lesions of them proved to be malignant and one proved to be benign. There are 6 lesions showed mixed restricted and facilitated diffusion proved to be malignant. Conclusion: DWI improves the diagnostic ability of the DCE-MRI of the breast. It is a better method for detecting breast lesions than either T 1 -or T 2 -weighted imaging, but it is better to be performed in conjunction with contrast enhanced MRI.