Background & Objective:Telomere-related tumorigenesis mechanisms in the salivary gland, including mutation in the promoter region of TERT, have been rarely investigated. Therefore, the present study aimed to investigate the mutation in the promoter region of TERT in benign and malignant salivary gland tumors.Methods:This was a descriptive-analytical cross-sectional study. Tissue samples of 54 patients with primary salivary gland tumors sent to the pathology department of Rasool-e-Akram Hospital from September 2017 to September 2021 were examined. Fifteen samples including two groups of the most common benign tumors (n=5; 3 pleomorphic adenomas and 2 Warthin tumors) and four groups of the most common malignant tumors (n=10; 3 mucoepidermoid carcinomas, 3 adenoid cystic carcinomas, 2 acinic cell carcinoma, and 2 salivary duct carcinoma) were selected. The promoter region of TERT, including well-known hot spot regions, is sequenced using the Sanger sequencing method. Data were analyzed using statistical software R version 4.1.2.Results:Of 15 salivary gland tumor specimens, consisting of 5 benign tumors and 10 malignant tumors after DNA sequencing, TERT promoter region mutation was only seen in one of the adenoid cystic carcinoma samples, located at -146 bp upstream from ATG (chr5: 1,295,250 C>T).Conclusion:TERT promoter mutation was not different in malignant and benign salivary tumors. Nonetheless, there are a few studies that report TERT promoter mutation in adenoid cystic carcinoma of the salivary gland, necessitating the need for further investigations.