The compelling evidence that blood glucose control will slow or prevent microvascular complications has stimulated research to find better ways of managing insulin-dependent diabetes. The excellent results obtained with "open loop" insulin infusion systems suggest that the relative failure of conventional treatment is the result of (1) a lack of appropriate feedback to the patient and (2) the use of insulin regimens which do not mimic physiologic insulinemia, particularly in the basal state. Doctors regard blood glucose measurements as an essential part of diabetic management and extension of this technology to patients has added a new dimension, particularly in the assessment of control. Nevertheless, home blood-glucose monitoring will not necessarily improve diabetic control; the best results have been obtained when it has been offered as part of a package deal which includes more investment of time and interest by patients and doctor together with joint discussions of problems and changes in treatment. The biggest problem with conventional twice daily insulin regimens is to sustain constant basal insulin levels during the night. Attempts to obtain fasting normoglycemia with an injection before supper often result in nocturnal hyperinsulinemia and hypoglycemia. This can usually be resolved by changing to a three times daily regimen with an extra injection of NPH insulin at bedtime. Three times daily insulin injections with feedback from home blood-glucose monitoring give as good blood glucose control as infusion systems and are cheaper and more acceptable to patients.