Background: Breast cancer (BC) is the most common type of cancer among women world-wide and leading cause of cancer related deaths. Distant metastases are responsible for the majority of cancer-related deaths. Epithelial–mesenchymal transition (EMT) is defined by the loss of epithelial characters and acquisition of mesenchymal phenotype. Through EMT, tumor cells acquire fibroblast like properties and exhibit increased motility, helping the escape of tumor cells from the primary tumors and metastasis. Fibronectin (FN) is an extracellular matrix glycoprotein constituting an important part of the tumor associated stroma. It is also considered a mesenchymal marker of EMT. Objectives: Investigation of immunohistochemical expression of FN by epithelial and stromal cells of female BC and correlation of this expression with the clinico-pathological aspects of the tumors. Materials and methods: 50 formalin fixed paraffin embedded BC tissue sections were randomly collected. All the available data were collected from the patients’ reports. The paraffin blocks were sectioned stained with hematoxylin & eosin stains for histologic evaluation. Additional sections were immunostained with FN. Fibronectin expression was studied separately in the tumor cells and tumor stroma. Results: Epithelial FN expression was detected in 52% of cases and showed no statistically significant correlation with any of the studied parameters (P value > 0.005). Stromal FN expression was strong in 16%, moderate in 36% and negative or mild in 48% of our cases. It showed statistically significant correlation with the tumor desmoplasia (P=0.03) and presence of single mass (P=0.011). Epithelial and stromal FN expression positively correlated. Conclusion: Our results are in favour of the EMT theory, where epithelial FN expression was detected in 52 % of the cases.