OBJECTIVE: Implementing an internet-based managed care model for diabetes care in Switzerland. METHODS: The CareCard Diabetes is a national standard for diabetes care in Switzerland. In a joint approach the largest Swiss health insurance and an urban general practitioners' association have launched a joint quality assurance initiative for diabetes care in Luzern. An Internet quality assurance database is used to connect the physicians. Data from the CareCard were supplemented with specific anamnestic data and information regarding diabetes medication in order to allow for cost-effectiveness and risk analyses. The data are presented to the physician in several ways. Most important is a weighted problem list as a feedback to the GP, which gives advice on how to improve the diabetes care for each patient. The diabetic has access to the online CareCard Diabetes and via web-interface or call-center, and the entry of self-control data is possible. The physician in return has access to the self-control data of the patient and can derive information for the optimisation of the therapy. Quality campaigns help to facilitate the use of the system and to promote widely accepted guideline knowledge into routine diabetes care. A proof-of-concept study in Luzern has started in June 2001, with currently 176 patients being enrolled. RESULTS: HbA1c values decreased in type 2 diabetes patients from 7.3% to 6.9% (p<0.05). Men initially had worse HbA1c levels and showed greater improvements -0.5% than women did -0.2% (p<0.05). Results from an additional HbA1c quality assurance campaign found a relevant deviation of practice measured HbA1c levels (mean 6.9 % +/- 1.4%) in comparison to reference laboratory measurements (mean 7.3 % +/- 1.4%). The study will end in June 2003. CONCLUSION: The CareCard Diabetes was found to be an up-to-date standard for implementing a quality of care initiative in Switzerland. The internet offers possibilities to extend the value of this originally paper-based tool for improving quality of diabetes care.