In recent years postchallenge or postprandial hyperglycaemia has been found to be an independent risk factor for cardiovascular comorbidities and all-cause mortality in impaired glucose tolerance (IGT) and type 2 diabetes. With the database of the Risk Factors in IGT for Atherosclerosis and Diabetes (RIAD) study, it was also shown that atherosclerosis as measured by intima-media thickness of the common carotid arteries was associated with 2-hour postchallenge glucose level when HbA1c was normal. Taken together there are now comprehensive and consistent data from pathophysiological as well as epidemiological studies that excessive post-load glucose excursions have acute and chronic harmful effects on the endothelium and vessel wall. This is supported by four outcome studies that included control of postprandial glucose to prevent cardiovascular disease: Diabetes Intervention Study (DIS), Kumamoto study, DIGAMI study, and STOP-NIDDM trial. Therefore, in addition to HbA1c and fasting blood glucose, postprandial glucose monitoring should be an integral part of treatment to prevent acute and chronic complications.