OBJECTIVES: To evaluate the metabolic effect of adding continuous glucose monitoring (CGM) to insulin pump therapy and the impact of CGM on medical resource utilization METHODS: Eighty-one adults & seventy-two children with Type 1 diabetes participated in a multicenter, randomized, controlled, cross-over study.  Following a one month run-in period, subjects were randomized to CGM Sensor-ON or Sensor-OFF arms for six months, following a four month wash-out period subjects crossed over to the other treatment arm for six additional months. Health care resources utilization data was collected for both arms at baseline and at each study visit. RESULTS: Sensor use significantly improved glycemic control resulting in an HbA1c reduction of  -0.43% in the intention to treat population. There was no statistically significant difference in the average total daily amount of insulin used between Sensor-ON and Sensor-OFF groups both in children or adults. There were statistically significant reductions in the average weekly number of finger-prick tests observed in Sensor-ON vs. Sensor-OFF period (-3 tests/week in adults and -5 tests/week in children,) resulting in 140€ (adults) and 234€ (children) yearly cost reduction.  There was no significant difference in the number of diabetes related hospitalizations but the duration of the stay tended to be less with Sensor-ON vs Sensor-OFF (Adults; 2.2 vs 2.5 days and Children;  1.5 vs 2.0 days). In the per-protocol population children missed significantly less days of school during the Sensor–ON vs. Sensor-OFF periods (13 vs 42 days, p=0.0046). CONCLUSIONS: Adding CGM to pump therapy significantly improved metabolic control in adults and children, without increasing insulin dosage and concomitantly reducing the number of finger-prick tests.  Using the sensor five or more days per week significantly reduced absence from school in children with type 1 diabetes.