A meta-analysis was performed to assess the association between the transcription factor 7-like 2 (TCF7L2) gene polymorphism rs7903146 (IVS3C > T) and gestational diabetes mellitus (GDM). A comprehensive search was conducted to identify all case-control or cohort design studies of the above-mentioned associations. The fixed or random effect pooled measure was selected on the basis of homogeneity test among studies. Heterogeneity among studies was evaluated using the I(2). Meta-regression was used to explore the potential sources of between-study heterogeneity. Publication bias was estimated using Egger's linear regression test. A total of 10 studies including 3404 cases and 6473 controls were involved in this meta-analysis. Overall, after excluding articles that deviated from HWE in controls, and further the key contributors to between-study heterogeneity, significant associations between TCF7L2 rs7903146 genetic polymorphism and risk of gestational diabetes mellitus were observed in the dominant (OR 1.653, 95% CI 1.416-1.930) and codominant (OR 1.525, 95% CI 1.350-1.723) models. The meta-analysis suggests that TCF7L2 rs7903146 genetic polymorphism was associated with increased risk of gestational diabetes mellitus.