Objective: To investigate the impact of Ki-67 expression level on efficacy of neoadjuvant chemotherapy (NAC) in breast cancer patients. Methods: A total of 261 patients with relatively complete clinicopathologic data undergoing NAC were collected. The relations of pathological complete response (pCR) after NAC with Ki-67 expression and other clinicopathologic factors such as molecular subtype and hormone receptor status of the patients were analyzed. Results: The results of univariate analysis showed that pCR after NAC of the patients was significantly related to the status of progestrone receptor (PR) and epidermal growth factor receptor 2 (Her-2) as well as molecular subtype and Ki-67 expression; the results of multivariate analysis revealed that only the Ki-67 expression level was the independent predictive factor for pCR after NAC (OR=5.476, 95% CI=2.637–11.372, P<0.05). In addition, among the patients with positive estrogen receptor (ER) expression, the pCR rate in cases with high Ki-67 expression was 4.282-fold of that in those with low Ki-67 expression (OR=4.282, 95% CI=1.694–10.825, P=0.002), in PR positive cases was 0.303-fold of that in PR negative ones (OR=0.303, 95% CI=0.113–0.810, P=0.017), and in Her-2 positive cases was 2.607-fold of that in their negative counterparts (OR=2.607, 95% CI=1.023–6.642, P=0.045). Conclusion: In breast cancer patients, high Ki-67 expression level is a predictive indicator for high pCR rate after NAC. Meanwhile, it may be helpful for better individualized NAC planning with combined considerations of the status of other hormone receptors.