Conventional insulin treatment used during the latter part of this century has been unsuccessful in giving most patients with insulin-dependent diabetes mellitus (IDDM) a long normal life. During the last 10 years, however, our knowledge has improved dramatically. We concluded in 1987: "The accumulating evidence for the relationship between blood glucose control and the development and progression of diabetic microangiopathy, and the demonstration that early microangiopathy responds favourably to nearnormoglycaemia, calls for action to improve the care for diabetics. The question regarding blood glucose control is not in essence 'why', but 'how'?" [1]. This statement was based on the results from several Scandinavian trials which started 10-12 years ago [1][2][3][4][5][6][7]. Since then further evidence has strengthened the basis of the above conclusion, particularly results from the Stockholm study [8] and the Diabetes Control and Complications Trial (DCCT) [9]. In this review we will summarize the evidence of the benefits of near-normal blood glucose control on the development and progression of late diabetic complications, we will also focus on important areas of future research and how they apply in the clinical environment.