In diabetic patients the incidence of cardiovascular diseases (CVD) is higher compared with those without diabetes. This elevated incidence may be due to an increased prevalence of established risk factors, such as obesity, dyslipidemia and hypertension. However, several other determinants must be considered. Attention must be paid to the role that specific factors strictly related to diabetes, insulin-resistance and post-prandial hyperglycemia, play in the etiopathogenesis of CVD, as for example atherosclerosis. This review acknowledges the incidence of diabetes on cardiovascular diseases and atherosclerosis from endothelial dysfunction to plaque destabilization, suggesting that insulin resistance and postprandial hyperglycemia should be considered keys in the generation of these worst diabetic cardiovascular outcomes. It finds in hyperglycemia the primum movens that mediates the cascade of vascular damaging events from the beginning of ROS formation to plaque rupture, through increased inflammation. It also adds insights of why diverse therapeutic interventions, which have in common the ability to reduce oxidative stress and inflammation, can impede or delay the onset of complication of atherosclerosis in diabetic patients.