Objective: To study the expression and clinical significance of p73( in breast carcinomas. Methods: The expression of p73( was detected by immunohistochemistry in 41 breast carcinoma tissues, 13 benign breast tumor tissues and 8 normal tissues and 8 normal breast tissues, respectively. Results: The positive expression of p73( was found in 20/41 (48.8%) of breast carcinoma tissues, 1/13 (7.7%) of benign breast tumor tissues. The positive expression rate of p73( in breast carcinoma tissues was significant1y higher than that in benign breast tumor tissues and normal breast tissues (P<0.05). The expression intensity of p73( increased significantly in breast carcinoma tissues compared with benign breast tumor tissues and normal breast tissues (P<0.05). Significant association of the expression of p73( with lymph node metastases and TNM stages of the carcinoma was found (P<0.05). The expression of p73( displayed a positive correlation with p53 (P<0.05). Conclusion: These results suggest that there is an up-regulation of p73( expression in breast carcinoma tissues, which may be implicated in the tumorigenesis of breast carcinoma as a molecular alteration.