ABSTRACT Background: Most of breast cancer related deaths are caused by local invasion and distant metastasis identifies the factors underlying invasion and metastasis to develop novel treatment strategies and improve survival. Accordingly, this study aimed to investigate the immunohistochemical expression of aquaporin-3 (AQP3) and Epithelial Mesenchymal Transition related proteins (E-cadherin and vimentin) in invasive breast carcinoma of no special type (IC NST), and analyze their prognostic impact in these cases. Materials and methods: Immunohistochemical expression of AQP3, vimentin and E-cadherin in 50 paraffin embedded specimens of IC NST. The relationship between their expressions with the clinicopathological variables and patient survival were evaluated. Results: our results revealed that positive AQP3, as well as positive vimentin expression, was significantly associated with high tumor grade, large tumor size, lymph node metastasis, distant metastasis, advanced tumor stage, ER negative and triple negative cases. While negative E-cadherin expression was significantly correlated with high tumor grade, large tumor size, lymph node metastasis, distant metastasis and advanced tumor stage. A significant positive correlation between AQP3 and vimentin expression was found, while E-cadherin expression showed a negative correlation with both markers. A significant association was found between positive AQP3, positive vimentin and negative E-cadherin expressions with high tumor recurrence, shorter 3 years disease free survival and overall survival Conclusion: Positive AQP3, positive vimentin and negative E-cadherin expressions are considered as adverse prognostic markers and may predict. In addition, AQP3 may play important role in breast cancer progression, invasion and metastasis by induction of Epithelial Mesenchymal Transition