Human telomerase reverse transcriptase (hTERT) is the catalytic subunit of human telomerase and its rate-limiting component. The purpose of the present study was to investigate the diagnostic value of hTERT in serum of cervical cancer patients. Preoperative values of hTERT, squamous cell carcinoma antigen (SCC-ag) and cancer antigen 125 (CA 125) were measured by enzyme-linked immunosorbent assay (ELISA) in 192 patients with squamous cell carcinoma or adenocarcinoma of the uterine cervix and 38 healthy controls. Elevated pretreatment levels of hTERT were identified in 80.2% of squamous cell carcinoma and 73.8% of adenocarcinoma patients. The expression of serum hTERT was correlated with telomerase activity in cancer tissues of both histological types. Pretreatment serum hTERT levels showed a significant correlation with clinical stage, tumor size and lymph node metastasis, but not with age. Serum hTERT measurement was found to be useful in the diagnosis and assessment of clinical stage of cervical cancer, and to be superior to the conventional tumor markers. Therefore, serum hTERT is a novel and readily available marker for cervical malignancies.