Telomerase is a specialized enzyme which maintains telomere length at the extreme end of the chromosome. Over 90% of all cases of cancer show high expression of telomerase while in normal cells, its expression is extremely low or undetectable. Detection of telomerase activity in a wide range of breast cancer makes telomerase an interesting target for diagnosis and therapy. In this review, we have aimed to describe telomerase as a therapeutic and accurate diagnostic target in breast cancer. Telomerase performs many extracurricular activities apart from maintaining telomere length; here, we have also tried to address its role in epithelialmesenchymal transition (EMT) of breast cancer progression.