Postprandial hyperglycaemia is a phenomenon often neglected by patients as well as doctors. While patients only voluntarily measure morning and preprandial capillary glycaemia, physicians do not encourage the measurement of anything further. The specific role of postprandial hyperglycaemia in the determination of late diabetes complications, such as micro- and macroangiopathy, remains controversial. It is however undeniable that the postprandial glycaemic excursion plays an important role in total hyperglycaemia reflected by an increase in glycated haemoglobin. The postprandial glycaemia measurement or, more appropriately, the postprandial glycaemic excursion (the difference between postprandial and preprandial glycaemia, also called the postprandial delta glycaemia), is important to measure and there are specific tools to correct it when abnormal. Postprandial delta glycaemia should lie between 30 and 50 mg/dl. It is thus suggested to measure it not necessarily on a daily basis, but when it is expected that the glycaemic couple, or "pre-postprandial couple", is high. The specific tools for treatment of postprandial hyperglycaemia can be dietetic (carbohydrate quantity reduction or ingestion of fiber-rich and/or low glycaemic index foods) or medicinal. Among the specific medicinal treatments are the alpha-glucosidase-inhibitors (which can be used for both type 1 and type 2 diabetic patients), glinides and fast-acting insulins. Rather than first treating fasting and interprandial hyperglycaemia, as has been commonly done by physicians, the authors recommend the simultaneous treatment of pre-, inter- and postprandial hyperglycaemia. The optimal time at which to evaluate postprandial glycaemia is approximately 1 h and 15 minutes for type 1 and type 2 diabetic patients.