Objective : To determine whether use of the internet-based Carelink system improved glycemic control in children on insulin pump therapy. Research Design and Methods - We reviewed records of 146 children treated with insulin pump therapy between the years 2004-2007, and compared glycemic control and diabetes self-care measures associated with Carelink use. Forty percent of the patients resided one hour or more from our clinic. Results: Patients who used the Carelink software and website showed significant improvement in HbA1c levels following use (8.0 ± 0.1 (SE) vs 7.7 ± 0.1 (SE), p=0.002). They uploaded data from their pump and glucometer 2.2 ± 1.8 times per month over 0.8 ± 0.4 (SD) years. Patients who had no access to Carelink software and were followed in a conventional manner showed no change in HbA1c ( 8.0 ± 0.1 (SE) vs 8.1 ± 0.1 (SE), p=0.27) during the study period. These patients did not differ significantly from Carelink users in diabetes self care behaviors. Patients who had Carelink access but did not use it had a higher HbA1c level at the onset and did not change over the study period (HbA1c 8.9 ± 0.2 (SE) vs 8.9 ± 0.3 (SE), p=0.76). These patients differed significantly from Carelink users in self-care behaviors, but not in the frequency of blood glucose monitoring. Patients in a rural location benefited equally as compared to patients who lived within one hour of our clinic. Conclusions: The Carelink software program is a powerful tool that can be used by diabetes care providers and parents to manage insulin pump therapy in children and to improve glycemic control, especially in states with a large rural population