A strong relationship between long term metabolic control and low frequency of chronic diabetes complications was shown in the Diabetes Control Complication Trial (DCCT). However, the subcutaneous intensive insulin therapy required to achieve the glycemic goals defined by the DCCT led to an unacceptable frequency of severe hypoglycemia and a significant weight gain. This limits the benefits of this therapy and excludes groups of patients such as young children, the elderly or hypoglycemia prone patients. The intensive therapy and self blood glucose monitoring (SMBG) necessary to limit hypoglycemia represent a heavy burden for the patients and their family. Improvements in parenteral insulin therapy are possible by either modifying subcutaneous insulin characteristics (analogs, adjunction of peptides such as amylin, GLP1, IGF1), or by developing better routes of administration and making SMBG easier, which is a key to intensive insulin therapy success. The ultimate goal remains the development of an automated, glucose controlled device.