This article presents an introduction to diabetes and the problems associated with diabetes as well as scientific evidence on how to prevent or retard chronic complications diabetes causes by means of optimizing a diabetes sufferer's metabolic control. The authors make reference to one of the most important studies by The Diabetes Control and Complications Trial-DCCT which has signified a before and an after in the treatment of type 1 diabetes mellitus (DM1). Focusing on the treatment of diabetes with continuous subcutaneous insulin injection (CSII), the authors describe 1) Patients who are candidates for this treatment according to scientific associations; 2) Characteristics and functioning methods for insulin delivery systems as well as the different models of insulin delivery systems, catheters, needles and commercial inserting mechanisms presently available in Spain. The authors report on the experiences that the diabetes team at the Barcelona "Hospital Clinic" have with CSII therapy The authors describe the structure of a Therapeutic Educational Program directed at patients suffering from DM1 who are candidates for CSII therapy the process which these patients follow and the results of this program, evaluated after two years of follow-up study.