We evaluated a telemedicine system in patients with type 1 diabetes who had optimized treatment with an insulin pump and a real-time continuous glucose monitoring system. We conducted a prospective, one-year study of 15 subjects. Three medical visits took place: pre-baseline, baseline and at 6 months. Each month the subjects transmitted information from the glucose meter, glucose sensor and insulin pump. We adjusted the treatment and returned the information by email. We evaluated psychological and metabolic variables, including HbA(1c), hypoglycaemia, hyperglycaemia and glucose variability. At baseline the mean age of the subjects was 40 years and the mean duration of diabetes was 22 years. There was a significant reduction in HbA(1c) (7.50 to 6.97%) at 6 months, a significant increase in the number of self-monitoring blood glucose checks per day (5.2 to 6.2), and significant improvements in variability: MODD, mean of daily difference (67 to 53) and MAGE, mean amplitude of glycaemic excursions (136 to 102). There were significant improvements in quality of life (92 to 87), satisfaction with the treatment (34 to 32) and less fear of hypoglycaemia (36 to 32). Adult subjects with type 1 diabetes on treatment with a continuous insulin infusion system and a real time glucose sensor and who have acceptable metabolic control and optimized treatment can benefit from the addition of a telemetry system to their usual outpatient follow-up.