Objective： The C-type lectin 5A (CLEC5A) is a key protein involved in the inflammatory response. However, the role of CLEC5A in the prognosis and tumor-infiltrating immune cells (TILs) of Gastric cancer (GC) remains unclear. Methods：In the current study, the raw data on CLEC5A expression in GC were obtained from TCGA data bases. TIMER2.0, CIBERSORT and Tissue microarray (TMA) analysis (145 GC tissues, 36 normal gastric mucosal tissues) method were used to investigate the association between CLEC5A and TILs invasion. The roles of CLEC5A expression and clinicopathologic characteristics in prognosis of GC patients were analyzed by univariate and multivariate Cox regression analysis. Results：CLEC5A protein expression was higher in GC tissues (114/145, 78.6%) than in normal gastric mucosal tissues (13/36, 36.1%, p < 0.05), demonstrated by IHC scores in TMA. Multivariate Cox regression analysis revealed that the up-regulated CLEC5A expression in tumor cells was associated with better overall survival (OS) of GC cases. Moreover, high CLEC5A expression in TILs was correlated with lower N stage and lower CEA level (p < 0.01). Specifically, a positive correlation was identified between increased CLEC5A expression and the more TILs using TIMER2.0 and CIBERSORT analysis. The Multiplex immunohistochemical (mIHC) demonstrated that that the expression of CLEC5A is associated with TILs, and CD4+T The infiltration levels of CD8+T, CD45RO+, FOXP3+T, PD1+, and PDL1+cells were higher in the low expression group (p < 0.05). Conclusion：Together, these results indicated that up-regulated CLEC5A expression correlated with the increased proportion of immune cells and favorable prognosis in GC.