Diabetes is characterized by glycaemic disorders that include both sustained chronic hyperglycaemia and acute fluctuations (i.e. glycaemic variability). Increasing attention is being paid to the role of glycaemic variability as a relevant determinant for diabetes control and prevention of its vascular complications. As a consequence, it is strongly suggested that a global antidiabetic strategy should be aimed at reducing to a minimum the different components of glycaemic control (i.e. HbA1c, fasting and postprandial glucose, as well as glycaemic variability). Subjects at risk of hypoglycaemia, subjects with postprandial hyperglycaemia and patients who need to adjust or start insulin seem to be the categories that require glycaemic variability monitoring. The analysis of blood glucose variability represents an additional tool in the global assessment of glycaemic control and can serve as a guide to the clinician in the management of therapy and for the patients both in the prevention of acute complications, in particular hypoglycaemia, and chronic disease, in particular macrovascular complications.