Purpose: To evaluate the correlation between dynamic MRI parameters and ADC values with histological grading in breast cancer. Patients and methods: Thirty patients with BIRADS V lesions on mammography were included in the study. MRI examination included conventional sequences ; diffusion weighted imaging and dynamic contrast enhanced magnetic resonance imaging. Morphological features, dynamic parameters and ADC values were recorded and correlated with with the histological grades. Results: A statistically significant inverse correlation between ADC value and histological grade was found. Tumors with higher grade showed lower ADC value compared with those of lower grade (p= 0.001). The mean ADC values of grade I, II and III were 0.96 ± 0.09 × 10-3 mm2/s, 0.89 ± 0.11 × 10-3 mm2/s and 0.76 ± 0.07 × 10-3 mm2/s, respectively. Also, high grade tumors (grade III) were more associated with washout dynamic curve compared to those with lower grades (grades I and II) (p= 0.04). However, no correlation was found between the maximum relative enhancement and the grade. Conclusion: DWI using ADC mapping is the most reliable technique to differentiate between different histological grades of breast carcinoma.