Neoadjuvant chemotherapy (NCT) is one of the main treatment strategies for patients with locally advanced breast cancer. In this study, we focused on the predictive and prognostic value of Ki-67 in triple-negative breast cancer (TNBC) patients who received NCT. Data from 280 patients with stage II-III TNBC were collected. All patients were treated according to the same protocol with weekly paclitaxel and carboplatin. The overall pCR rate was 33.9%. Both the categorical and linear Ki-67 were independently correlated with pCR (P < 0.001). There were also statistically significant differences among Ki-67 categories with respect to clinical response (P < 0.001), Miller-Payne (MP) grades (P < 0.001), and node status (P < 0.001). A significant reduction of Ki-67 after NCT was most likely observed in patients with a relatively better response. In the multivariate model for non-pCR patients, Ki-67 reduction presented an independent prognostic value for relapse of disease (HR = 0.986, 95% CI: 0.978-0.994; P = 0.001). This study had indicated that the primary Ki-67 might help in further classifying TNBCs into subtypes with different responses to chemotherapy and a significant reduction of Ki-67 after treatment could indicate a favorable prognosis in non-pCR patients.