This paper presents the DIABTel Telemedicine Service to support daily care of diabetic patients. The telemedicine system relies on three basic telemedicine services: telemonitoring, telecare, and teleeducation of patients. The system architecture is comprised by two main components: a Medical Workstation to be used by physicians at a hospital diabetes day center unit, and a Patient Unit, to be used during the patients daily living. The main features of the new approach to diabetes care provided by the DIABTel service are: 1) to provide both patients and doctors an integrated service to manage and improve several areas of daily diabetes care; 2) the continuous analysis of incoming patients monitoring data, based on the telemonitoring service 24-hour call center, providing patients with what we called a “supervised autonomy” during their ambulatory monitoring process; 3) the remote assistance of patients on treatment modification; 4) the decrease of the time response therapy adjustment, enhancing the patient’s self-management and education; 5) the improvement of the quality and quantity of patient’s monitoring data, facilitating the follow-up of an increased number of patients without decreasing their quality of care; and 6) the optimization of the number of patient’s visits to the hospital, but providing them, at the same time, a better access to clinical and monitoring data. A discussion of practical problems, limitations and critical implementation issues of the Telemedicine service are also presented.