There is no clinically applicable tumor marker for head and neck cancers. Telomerase is detected in approximately 90% of all malignant tumors, it may predict poor or favorable outcomes, thus being both a highly attractive biomarker and a target for the development of molecular-based cancer diagnostics, prognostics, and therapeutics. Primary aim was to detect a change of telomerase activity before and after curative treatment. Patients with biopsy proven head and neck squamous cell carcinoma, stage I-IVB treated with a curative intent, performance status 0-2 and malignancy at one primary site were included in the study. Telomerase levels were tested in tissue biopsy. Plasma telomerase levels were tested at baseline, 5 days and at 3 months after treatment using ELISA. Raised plasma telomerase activity was seen in all the patients with cancer at baseline. The mean plasma telomerase level at baseline was 861.4522ng/ml, at 5 days after completion of curative treatment was 928.92ng/ml and at 3 months of follow up was 898.87ng/ml. The mean tissue biopsy telomerase level was 19768.53ng/mg. There was a significant increase in baseline telomerase levels in cancer patients compared to normals (volunteers) (t=-3.52, p=0.001).There was a significant increase in plasma levels of telomerase at 3 months compared to baseline values (z=-1.98, p=0.04). The increase in telomerase level did not correlate with the response of the treatment. In patients with head and neck squamous cell carcinomas treated with a curative intent, the change in levels of telomerase correlates neither with the disease status nor with prognostic factors.