The transforming growth factor-β1 (TGF-β1) gene 29 T/C polymorphism is thought to be associated withbreast cancer risk. However, reports are largely conflicting and underpowered. We therefore conducted a metaanalysisof all available case-control studies relating the TGF-β1 29T/C polymorphism to the risk of developingbreast cancer by including a total of 31 articles involving 24,021 cases and 31,820 controls. Pooled ORs weregenerated for the allele contrasts, with additive genetic, dominant genetic and recessive genetic models. Subgroupanalysis was also performed by ethnicity for the TGF-β1 29T/C polymorphism. No association was found in theoverall analysis (C vs T: OR=1.028, 95% CI=0.949-1.114, p-value 0.500; CC vs TC: OR= 1.022, 95% CI=0.963-1.085, p-value 0.478; CC vs TT: OR= 1.054, 95% CI=0.898-1.236, p-value 0.522; CC vs TT+ TC: OR= 1.031, 95%CI=0.946-1.124, p-value 0.482; TT vs CC+TC: OR= 0.945, 95% CI=0.827-1.080, p-value 0.403). Similarly, in thesubgroup analysis by ethnicity, no association was found in Caucasian (C vs T: OR= 1.041, 95% CI=0.932-1.162,p-value 0.475; CC vs TC: OR= 1.031, 95% CI=0.951-1.118, p-value 0.464; CC vs TT: OR= 1.081, 95% CI=0.865-1.351, p-value 0.493; CC vs TT+TC: OR= 1.047, 95% CI=0.929-1.180, p-value 0.453; TT vs CC+TC: OR= 0.929,95% CI=0.775-1.114, p-value 0.429;) and Asian populations (C vs T: OR= 1.004, 95% CI=0.908-1.111, p-value0.931; CC vs TC: OR= 0.991, 95% CI=0.896-1.097, p-value 0.865; CC vs TT: OR= 1.015, 95% CI=0.848-1.214,p-value 0.871; CC vs TT+TC: OR= 1.000, 95% CI=0.909-1.101, p-value 0.994; TT vs CC+TC: OR= 0.967, 95%CI=0.808-1.159, p-value 0.720;). No evidence of publication bias was detected during the analysis. No significantassociation with breast cancer risk was demonstrated overall or on subgroup (Caucasian and Asian) analysis.It can be concluded that TGF-β1 29T/C polymorphism does not play a role in breast cancer susceptibility inoverall or ethnicity-specific manner.