Telemedicine systems have been proposed as a means of supporting people with diabetes in the self-management of their condition. Requirements for monitoring parameters of care, including glycaemic control, extent of analysis and interpretation of data, patient-clinician contacts, and involvement of a multidisciplinary care team with effective communication, can be addressed by telemedicine systems. We describe the development and implementation of an innovative real-time telemedicine system based around transmission and feedback of data to and from a mobile phone. Proprietary Java-based programs were used to link a blood glucose meter to a mobile phone. In addition to immediate transmission of blood glucose data, information about insulin dose, eating patterns and physical exercise were collected. Immediate feedback to the phone included a colour histogram to draw attention to levels of control over glycaemia over the previous two weeks. Clinicians supporting patients had access to summary screens identifying users not testing, and those with levels of blood glucose outside pre-defined limits. More detailed graphical displays of data were used to provide data about control of insulin dose and the degree to which it was modified in response to diet and exercise. The system has been evaluated in a clinical trial conducted in secondary care and is now being adapted for use in a trial in primary care, which is designed to assess its effectiveness in providing integrated management for the patient, general practitioner and pharmacist.