ObjectiveTo investigate the relationship between the aldehyde dehydrogenase 2 gene (ALDH2) polymorphism and carotid intima-media thickness (IMT). MethodsFrom April 2013 to February 2014, 310 cases of carotid IMT thickening (IMT thickening group) from the physical examination center were included in the study and 280 cases of normal carotid IMT were regarded as controls. DNA was extracted from peripheral blood. ALDH2 gene polymorphism was detected by DNA microarray method. ResultsGenotype distributions had no deviation from Hardy-Weinberg equilibrium in both groups. Compared with controls, the frequency of AA/AG genotypes (67.4%, 41.1%; P<0.01) and the frequency of A allele (37.9%, 22.3%; P<0.001) of ALDH2 gene were apparently increased in the subjects of IMT thickening group. There was a significant difference in the frequency distribution of genotype and allele in ALDH2 between the two groups. The logistic analysis showed that the ALDH2 gene polymorphism was associated with the increased carotid IMT [OR=2.381, 95%CI (1.356, 4.213), P=0.004]. ConclusionThe ALDH2 gene polymorphism is correlated with the increased carotid IMT in the Han population of China Sichuan. The ALDH2 gene polymorphism may play an important role in genetic susceptibility of increased carotid IMT.