BACKGROUND: Claudins are tight junction proteins , their expression is often different in normal and corresponding tumor cells. The altered expression of selected claudins has been reported in several human cancers and have previously been associated with process of tumor progression , the aim of this study was to evaluate expression of claudin-4 in selected benign and malignant salivary gland neoplasms. METHODS: Detection of Claudin-4 protein expression score by immunohistochemistry in a total of 56 specimens including normal salivary tissue, pleomorphic adenoma, Warthin’s tumor and mucoepidermoid carcinoma. RESULTS: A highly significant difference was obtained on comparing the total scores of claudin-4 immunoexpression among studied groups , the overall expression of claudin-4 decreased significantly from normal control to benign salivary gland neoplasms and reached its lowest values in malignant salivary gland neoplasms . CONCLUSIONS: Decreased claudin-4 protein expression in malignant salivary gland neoplasms is accompanied by a disruption of tight junctions, a process that may play a key role in loss of cohesion and invasive¬ness observed in cancer cells.