Polyphenols are a large and heterogeneous group of phytochemicals containing phenol rings and are divided into flavonoids, phenolic acids, stilbenes, and lignans. Among all polyphenols, the beneficial effects of flavanols (flavan-3-ols) and their primary food sources, including cocoa, chocolate, and red wine, have been most widely examined in clinical trials. Polyphenols can exert a beneficial effect on type 2 diabetes by a number of mechanisms including slowing carbohydrate digestion and glucose absorption by interacting with oral cavity and intestinal α-amylase and intestinal α-glycosidase and sodium-dependent glucose transporter and by stimulating insulin secretion in the pancreas via increasing 5′ adenosine monophosphate-activated protein kinase (AMPK) pathway, and insulin receptor substrate (ISRS) and decreasing β-cell oxidative damage which preserves β-cell integrity. In present paper we have discussed briefly about the role of ployphenols and diet rich in polyphenols contains antioxidant which help in management of diabetes induced by oxidative stress. we also highlight the mechanism of oxidative stress in induction of diabetes and role of antioxidants in management of diabetes mellitus.