The effects of subcutaneous and intraperitoneal insulin delivery by a closed-loop insulin infusion device on post-prandial hyperglycaemia and rates of glucose appearance and disappearance were compared in alloxan diabetic dogs. No differences in basal or post-prandial values or patterns of response were observed between the two routes of insulin delivery. In addition, the amounts of insulin infused and the plasma insulin concentrations achieved were not different for the two routes of insulin administration. These studies demonstrate that in the dog there appears to be no difference in the pattern of disposal of glucose from a mixed meal when insulin was administered intraperitoneally or subcutaneously at the rates of insulin infusion used in these experiments.