Loss of expression of cadherin-11 protein is correlated with a loss of epithelial phenotype and a gain in tumor cell proliferation and invasion. It has been hypothesized that cadherin-11 may be a molecular marker for a more aggressive subtype of breast cancer. The present study examined the expression of the mesenchymal gene/protein cadherin‑11 in malignant, benign and healthy breast cancer samples. A paraffin‑embedded tissue microarray of both malignant and benign/healthy breast tumor was used. Clinicopathological parameters, including age, grading, tumor size, hormone receptors and HER2 receptors status were obtained from patient medical records. Expression of cadherin‑11 was analyzed using the monoclonal mouse anti cadherin‑11 IgG2B clone. Total RNA was extracted from each breast cancer sample and subjected to semi‑quantitative RT‑PCR analysis for cadherin‑11. Cadherin‑11 was detected in 80/82 malignant breast cancer samples and in 33/70 non‑malignant tissue samples. Cadherin‑11 expression was observed to be predominantly localized to the membrane of tumor cells. When compared to healthy breast tissue biopsies, both cadherin‑11 mRNA and protein were demonstrated to be significantly overexpressed in breast carcinoma (P= 0.040 and P< 0.0001, respectively). Within malignant tumors, however, protein expression was not identified to be associated with other clinicopathological parameters. Our results indicate that cadherin‑11 expression is upregulated in malignant human breast cancer.