Objective: To investigate the value of magnetic resonance elastography (MRE) in evaluating the histological grade of breast cancer. Methods: From April 2023 to May 2025, 120 breast cancer patients underwent conventional MRI and MRE examinations before treatment. Tumor elasticity values were measured, and the relationship between tumor stiffness and histological grade was analyzed. Results: Among the 120 breast cancer patients, 9 had histological grade I, 68 had grade II, and 43 had grade III. Apart from the maximum tumor diameter, there were no statistically significant differences in conventional MRI features such as margin morphology, enhancement pattern, TIC (time-intensity curve) type, glandular tissue type, and peritumoral edema between grade I-II and grade III tumors (P > 0.05). Statistically significant differences were observed in MRE elasticity values among patients with different maximum tumor diameters and histological grades (P < 0.001). Specifically, the MRE elasticity values for histological grades I-II and III were (2.74 ± 0.23) kPa and (3.31 ± 0.39) kPa, respectively. Correlation analysis revealed a positive correlation between MRE elasticity values and both maximum tumor diameter and histological grade in breast cancer patients (rs values were 0.527 and 0.826, respectively, with P < 0.001). The ROC curve was plotted, showing that the AUC (area under the curve) for MRE elasticity values in diagnosing grade I-II and grade III tumors was 0.857, with a cutoff value of 3.17 kPa, a sensitivity of 83.6%, and a specificity of 84.9%. Conclusion: MRE demonstrates good predictive value for the histological grade of breast cancer, with higher elasticity values indicating higher histological grades, and holds promise for assisting in clinical decision-making.