The United Kingdom Prospective Diabetes Study (UKPDS) is the largest study ever performed in the field of diabetes. It has been carried on in more than 5000 patients with newly diagnosed type 2 diabetes and followed during almost 15 years. The main goals of the study were to investigate the effects of improving blood glucose and/or blood pressure control on diabetic complications, and to compare the advantages and inconvenients of the most important pharmacological approaches. The results of the UKPDS have been presented at the last Congress of the European Association for the Study of Diabetes (EASD) in Barcelona, September 10-11, 1998. They essentially showed that improving blood glucose or arterial blood pressure control allows to significantly reduce the incidence of complications associated to diabetes. Best results were observed in individuals in whom treatments of both hyperglycemia and hypertension were intensified. For each risk factor, no threshold has been found so that every reduction in blood glucose or arterial pressure is accompanied by a nearly linear diminution in the incidence of diabetic complications. The type of pharmacological treatment appears to have a less prominent influence, even if metformin appears to exert the most favourable effects in the group of obese patients with type 2 diabetes.