Glu298Asp polymorphism of the endothelial nitric oxide synthase eNOS gene (NOS3) has previously been identified as a risk factor for hypertension and coronary artery disease. Studies suggest that the higher risk observed in thymine (T) allele carriers is due to endothelial dysfunction associated with lower eNOS activity. It has been proposed that acute consumption of nitrate ameliorates postprandial endothelial dysfunction possibly by the donation of nitric oxide by a mechanism that does not rely on eNOS. Nevertheless, how these factors interact has yet to be determined. Therefore, the aim of this study was to investigate whether the presence of NOS3 Glu298Asp polymorphism interacts with the nitrate content of beetroot-enriched bread to influence postprandial blood pressure.