ABSTRACT. Numerous studies have evaluated the association between Glu504Lys polymorphism in the aldehyde dehydrogenase 2 (ALDH2) gene and colorectal cancer (CRC) risk. However, the specific association remains controversial. To assess the relationship between the ALDH2 Glu504Lys polymorphism and CRC, we conducted a comprehensive meta-analysis of five case-control studies comprising 1664 patients with CRC and 2777 controls. The results of this metaanalysis showed that the ALDH2 Glu504Lys polymorphism was associated with a significantly reduced risk of CRC [Lys/Lys vs Glu/ Glu: odds ratio (OR) = 0.95, 95% confidence interval (CI) = 0.58- was observed in our meta-analysis. Based on the statistical data, our meta-analysis indicates that the ALDH2 Glu504Lys polymorphism is associated with reduced risk of developing CRC.