The development of portable insulin infusion devices - in which the insulin dosage is programmed in advance (open loop system) are increasingly being used for long-term daily diabetes control. These pumps represent a new method for attaining significantly improved metabolic control (glycemia and glucose metabolites, HbA1, lipid and aminoacid metabolism) and an impressive influence on diabetic neuropathy, on general fitness and on quality of life of insulin-dependent diabetics. At least all insulin-dependent diabetics without noticeable residual insulin secretion should be treated by continuous subcutaneous insulin infusion (CSII) via portable pumps, that are 8 000-10 000 patients in the GDR and approximately 500 000 in the world. Considering special conditions (strict supervision by experienced medical staff, carefully drawn up adequate instructions, highly motivated and capable patients) we assume that at the present stage of technical development of the pumps infants, imbeciles and incooperatives should be excepted only.