Continuous subcutaneous insulin injection was used for the self-care of five patients aged 10-18 years with insulin-dependent diabetes mellitus. After an introduction to the concept and procedures for continuous subcutaneous injection, the patients soon became familiar with self-care using an insulin pump at home and at school. Three months later, the control of blood glucose improved with smaller doses of insulin in four cases and milder hypoglycemia was observed compared to when using multiple injections. Significantly decreased variations and lowered means of early morning blood glucose values were observed and seemed to explain the reason for better glycemic control. Buffered regular insulin continuously injected by pumps brought a more stable nocturnal blood glucose level compared to isophane insulin injected at bedtime, the absorption of which seemed to vary considerably. On the contrary, unbuffered regular insulin injected by pumps brought frequent nocturnal hypoglycemia, sudden worsening of glycemic control and skin infections and thus, was deemed inadequate for continuous subcutaneous injection.