This prospective, open-label study was designed to measure the impact of short-term infusion-set disconnects on glucose levels. Continuous subcutaneous insulin infusion therapy allows for uninterrupted delivery of insulin. Patients disconnect their insulin pumps from their infusion sets when showering, swimming, exercising, or during intimate moments. Interrupting insulin infusion results in cessation of basal insulin delivery. Nineteen subjects with type 1 diabetes were studied on two separate in-clinic days. One hour after arriving at the clinic in a fasting state, subjects either temporarily disconnected their infusion sets from their pumps, interrupting basal insulin infusion for 30 min, or, on a separate day, changed their infusion sets. Glucose levels were monitored for an additional 4 h on both occasions. Changing infusion sets did not affect short-term glucose control. However, the 30-min interruption of basal insulin infusion resulted in significant glucose elevation; approximately 1 mg/dl for each minute basal insulin infusion was interrupted.