A primary function of the vascular endothelium is its role in vascular homeostasis ensuring basal and dynamic vascular tone and function. Endothelial dysfunction (ED) has consequently been associated with the pathogenesis of cardiovascular diseases (CVDs). ED encompasses abnormal vascular growth/remodelling, impaired antithrombotic, anticoagulant and anti-inflammatory properties as well as predisposing to atherosclerosis. ED can also reduce nitric oxide (NO) bioactivity and increase oxygen free radical formation. It is established that oxidative stress can underpin the development of ED and consequent atherosclerosis. A number of human studies have evaluated the role of nutrition as a significant factor in mitigating ED with particular reference to foods/beverages rich in polyphenols and antioxidants. Of particular interest is the evidence on polyphenolic compounds such as flavonoids and its subclasses, assessing ED via structural and functional vascular measures. It is plausible that specific polyphenols and antioxidants may have preventative/therapeutic potential in reducing ED and oxidative stress. This presentation critically appraises and summarizes emerging evidence linking specific dietary antioxidants and polyphenols to vascular function and cardiovascular health.