The development of implantable, remote-controlled insulin pumps dates back to the early 1970's when it was recognized that conventional insulin therapy may be inadequate to control microvascular complications. For the first prototypes the intraperitoneal access route was favoured because of a physiological portal/peripheral insulin gradient. With intraperitoneal insulin delivery excellent metabolic control can be obtained with glycohaemoglobin values close to the upper normal range. Although long-term studies in insulin-dependent diabetic patients show comparable results with respect to glycaemic control and intermediary substrate levels with intensive conventional therapy, the advantage of intraperitoneal insulin delivery may lie in the low rate of hypoglycaemic episodes.