Mounting data have emerged suggesting that the Connexin37 C1019T polymorphism increases susceptibility to coronary artery disease (CAD). However, previous studies yielded conflicting results. In the current study, a comprehensive meta-analysis was performed to investigate whether the C1019T polymorphism is associated with CAD risk.A total of 11 studies examining the C1019T polymorphism and CAD were identified using MEDLINE, Embase, CNKI, Wanfang and CBM, in which 5535 CAD patients and 5626 controls were analyzed. A random-effects model was used to calculate odd ratios and confidence intervals, while addressing between-study heterogeneity. Publication bias was weighed using the Egger's test, Begg-Mazemdar test and funnel plot.In genetic models with striking heterogeneity, the risk of CAD was not associated with the C1019T polymorphism (allele comparison: p = 0.34, OR = 1.11, 95% CI 0.90-1.36). Stratification by disease endpoints indicated that the 1019T allele was significantly associated with myocardial infarction (MI) (allele comparison: p <0.001, OR = 1.59, 95% CI 1.24-2.03). Further meta-regression analysis indicated that a large proportion of heterogeneity was probably due to the varying proportions of diabetes mellitus (DM) across studies (p = 0.014).Our results indicated that the C1019T polymorphism may be a moderate risk factor for MI and that DM was likely a potential source of between-study heterogeneity.