BACKGROUND: The association between matrix metalloproteinase 9 (MMP-9) gene -1562C/T (rs3918242) polymorphism and the susceptibility of ischemic stroke (IS) has been investigated. However, results were ambiguous and inconsistent. Therefore, we performed this study to better assess the potential relationship between rs3918242 polymorphism and susceptibility risk of IS. METHODS: We included case-control studies concerning the relationship between the rs3918242 polymorphism and IS, and odds ratios with corresponding 95% confidence intervals were used to describe the associations. Furthermore, meta-regression analyses, heterogeneity, cumulative analyses, sensitivity analyses, and publication bias were examined. RESULTS: A total of 19 studies were included for analysis. Significant associations with the risk of IS were detected for the rs3918242 polymorphism in overall population, Asians, and whites. When available data were stratified by gender, we found a significant correlation with the risk of IS in both males and females. Further subgroup analysis by the subtypes of IS showed that the rs3918242 polymorphism was significantly correlated with the risk of patients with large artery atherosclerosis. When stratified by age, we found that the rs3918242 polymorphism was significantly correlated with the risk of IS in patients both aged >= 65 years and >65 years. Both the diabetes and the nondiabetes subgroups reached significant results, and in an analysis stratified by smoking status, an increased risk of IS was associated with smoking. CONCLUSIONS: The rs3918242 polymorphism may be a susceptible predictor of susceptibility of IS. Further large-scale studies are needed to verify the results of our findings.