Background: The preponderance of breast cancer-related deaths are the result of local invasion and distant metastasis; therefore, it is necessary to identify the factors underlying invasion and metastasis in order to develop novel treatment strategies and improve the survival of patients. In this regard, this study aimed to investigate the immunohistochemical expression and prognostic impact of aquaporin-3 (AQP3) and certain markers associated with epithelial-mesenchymal transition concerning invasive breast carcinoma of no special type. Method: Immunohistochemical expressions of AQP3, vimentin and E-cadherin were performed in 50 paraffin embedded specimens of such cases. We also assessed the relationship of their expressions with the clinicopathological variables and patients’ disease-free survival and overall survival. Results: There were significant associations between positive AQP3 and positive vimentin expressions and high tumor grade, large tumor size, lymph node metastasis, and advanced tumor stage. On other hand, negative E-cadherin expression had a significant correlation with high tumor grade, large tumor size, lymph node metastasis, distant metastasis, and advanced tumor stage. A significant association also existed between positive AQP3, positive vimentin and negative E-cadherin expressions and high tumor recurrence, short ‘three-year’ disease-free survival and overall survival. Conclusion: Positive AQP3, positive vimentin, and negative E-cadherin expressions are known as adverse prognostic markers and may predict survival in invasive breast carcinoma of no special type. It is proposed that AQP3 might play a role in breast cancer progression, invasion, and metastasis through induction of epithelial-mesenchymal transition.