Type I diabetes, the most common endocrinological disease in children and adolescents, is nowadays considered to be a genetically linked autoimmune disease. Clinical progression is divided into 3 phases: initial, remission and post-remission. Therapy consists of ketoacidotic compensation (when necessary), initial insulin dose adjustment, an organised education programme, and conventional insulin treatment with a mixture of normal and long-acting human insulins. Older children and adolescents (from age 12, or better, from age 14) are mostly treated with intensive conventional insulin therapy (ICT). The necessary long-term care of children and adolescents with diabetes should be carried out by a pediatric diabetic team. This team is in the position to recognise the special age-related problems in these patients and, based on adequate experience, can guarantee the best possible treatment. The aim must be the optimal, virtually near-normoglycaemic metabolic control already in childhood so as to avoid the threat of diabetic complications or at least to delay their onset.