Objective:To investigate the significance of telomerase activity in breast carcinoma with its respect to axillary lymph node status. Methods: Telomerase activity was analyzed in 88 breast carcinomas and 16benign breast lesions, using polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay. Results: Telomerase activity was detected in 75 (85%) of 88 breast carcinomas (including three breast carcinomas in situ which were all positive for telomerase activity), whereas in benign breast lesions analyzed only 2(12.5%) of 16 cases were positive for telomerase activity. The difference between the two groups was statistically significant (P＜0.001). Besides,telomerase activity was expressed significantly higher in node-positive breast carcinoma (93%) than in nodenegative ones (77%) (P＜0.05). Conclusion: Our results suggest that telomerase activation plays an important role during breast carcinoma development. It is possible that this enzyme may serve as an early indication of breast carcinoma.