OBJECTIVE- To determine whether real-time continuous glucose monitoring (CGM) with preset alarms at specific glucose levels would prove a useful tool to achieve avoidance of hypoglycemia and improve the counterregulatory response to hypoglycemia in adolescents with type 1 diabetes with hypoglycemia unawareness. RESEARCH DESIGN AND METHODS- Adolescents with type 1 diabetes with hypoglycemia unawareness underwent hyperinsulinemic hypoglycemic clamp studies at baseline to determine their counterregulatory hormone responses to hypoglycemia. Subjects were then randomized to either standard therapy or real-time CGM for 4 weeks. The clamp study was then repeated. RESULTS- The epinephrine response during hypoglycemia after the intervention was greater in the CGM group than in the standard therapy group. CONCLUSIONS- A greater epinephrine response during hypoglycemia suggests that real-time CGM is a useful clinical tool to improve hypoglycemia unawareness in adolescents with type 1 diabetes.