Nitric oxide (NO) is known to be critically involved in breast carcinogenesis. Genetic polymorphisms of the gene encoding for endothelial nitric oxide synthase (eNOS), the enzyme catalyzing the production of the NO, are known to predispose to malignant disease. Increasing evidences showed that eNOS plays a significant role in the development of breast cancer. However, published data on the association between eNOS 894 G>T polymorphism and breast cancer risk are inconclusive. In order to derive a more precise estimation of this relationship, a meta-analysis including 11 studies was performed. Crude odds ratios (ORs) with 95% confidence interval (CIs) were used to estimate the strength of the association. The results showed that there was a significant association with breast cancer risk in TT versus GG (OR = 1.22, 95% CI = 1.02-1.44, P = 0.272) and recessive model TT versus GG/GT (OR = 1.21, 95% CI = 1.02-1.42, P = 0.223). In summary, this meta-analysis primarily suggests that eNOS 894G>T polymorphism is associated with breast cancer.