Background: SIRT1 and claudin4 have been implicated in tumorigenesis in many cancers, but their significance in gastric carcinoma remains unclear. The aim of this study is to assess their possible significance in gastric carcinoma Methods: Immunohistochemistry was performed to examine the expression of SIRT1 and claudin4 in 68 cases of gastric carcinoma and 3 adjacent precursor lesions (chronic gastritis, intestinal metaplasia and dysplasia). Statistical analysis methods were used to evaluate the relationship between SIRT1 and claudin4 and various clinicopathological parameters. Results: SIRT1 and claudin4 were found highly expressed in gastric carcinoma. The two markers significantly correlated with depth of tumor invasion, distant metastasis and TNM stage. SIRT1 was positively correlated with advanced tumor grade while claudin4 was inversely correlated with it. No significant correlation between SIRT1 and claudin4 was detected. Conclusions: The results suggested that both SIRT1 and Claudin 4 might be involved in gastric carcinogenesis. The more advanced TNM GC stage, the higher expression of SIRT1 and claudin 4 suggesting their possible role in gastric carcinoma progression.