ABSTRACT Introduction: Breast cancer has a phenotype of interconnected epithelial cells and then changes to mesenchymal cells through activation of epithelial-to-mesenchymal transition (EMT). Vimentin, as the main component of forming a cell frame, can be used as a marker of the EMT process. Fibronectin is an extracellular glycoprotein that binds to receptor proteins known as EMT markers. This study aims to evaluate the correlation between these proteins on neoadjuvant chemotherapy (NAC) response. Methods: This study was carried out from November 2029 to March 2020 and used the consecutive sampling of Stage IIIA and Luminal Subtype IIIB breast cancer patients after chemotherapy using anthracycline. Subject obtained from outpatient at oncological surgery of Dr. Saiful Anwar Hospital Malang, Indonesia. Fibronectin and vimentin expression was measured from paraffin block by immunohistology staining. Statistical analysis used correlation tests and logistic regression with a significant level of P < 0.05. Results: Mean patient age in this study was 54 ± 4.5 years old, and most of the patients were Stage IIIB patients (98.48%). Most patients have negative vimentin and fibronectin expression. In this study, we found a significant relationship between vimentin expression and NAC response with P = 0.000 and a correlation coefficient was 0.440. Conclusion: There was a significant correlation between vimentin expression and the response of NAC. There is a significant correlation between fibronectin expression and the response of NAC. Fibronectin expression can be used as a predictive factor for nac in stage iiia breast cancer patients.