For Switzerland only sparse data exist on the actual implementation of such recommendations and on patient's well-being. The Swiss Diabetes Registry - SwissDiab Study is a prospective cohort study aiming at including and collecting data of virtually all patients regularly seen and treated at the study centers (≈ 500 patients each), irrespective of type, duration of diabetes or treatment . This allows the evaluation of diabetes treatment strategies at these centers. Furthermore, risk indicators for micro- and macrovascular complications, mortality as well as costs and quality of life will be assessed. Data will be recorded through an internet-based, electronic database specifically designed for this study. At a later perspective it is planned to extend data collection to general practitioner/family doctor networks in order to include a larger and more representative sample of patients with diabetes in Switzerland.