Intensive insulin treatment is defined by basal-prandial insulin therapy which tries to reproduce physiological insulin secretion. This requires 3 to 5 injections and self-monitoring of blood glucose 4 to 5 times a day. Patients who accept their disease and the demanding treatment regimen most often achieve HbA1(c) < 7.5%. Severe complications of diabetes can be avoided without increasing the risk of severe hypoglycemia. However, 50% of type 1 diabetic patients do not reach this objective. The reasons are: the disease itself, the diabetic patient, or the physician. Brittle diabetes with severe, repeated episodes of hypoglycemia and inversely persistent postprandial hyperglycemia prevents patients from reaching the ideal glycemic target. More often, the main obstacle is related to psychological problems: difficulties in self-regulation, denial of the disease, or phobia of hypoglycemia with avoidance behavior. Frequently, young women present eating disorders which can explain the poor diabetes control. The physician himself may be implicated in these poor glycemic results by not prescribing the right tools to obtain optimal glycemic control (staying with just two daily injections with premixed insulin) or by assigning glycemic targets inaccessible for the patient, or when an empathic relationship cannot be established between the patient and the physician. Patient empowerment is the key to the success of functional insulin treatment.