Diabetes is the fifth leading cause of death in Taiwan and the burden of suffering is still increasing. Building a comprehensive and efficient health care system is crucial to improve the outcome of the diabetics. We implemented the first diabetes shared care system of Taiwan in I-Lan County since August 1996 under the support of Department of Health, the Executive Yuan. This county-wide system was named 'Lan-Yang Diabetes Shared Care System' by the regional steering committee. Regional guidelines for diabetes management were developed after extensive discussion. A multidisciplinary diabetes care team was organized through a training and certification process. Registered patients held diabetes passports to keep clinical record. Physicians of the system use shared referral protocols and sheets. By the end of June 1999, 99 medical professionals had completed their training for diabetes shared care and been certified. The shared care system awarded 26 clinics to hang the lamp signs with the system logo to make them distinguishable. Such clinics have now been available throughout 12 townships in I-Lan County. The number of registered patients carrying diabetes passport increased to 3484 and there was a community-based patient group in every township of I-Lan County. The amount of continuing diabetes clinical training delivered by the specialists to the primary care physicians and non-physician professionals increased to 1681 person-hours per year. The proportion of registered patients undertaking fundus examination within 1 year increased to 30.9%, checking urine micro-albumin to 28.0% and checking HbA(1c) 72.8%, respectively. Mean HbA(1c) value decreased from 8.7% in the first year to 7.9% in the third year. Our study showed that under the co-ordination by regional health bureau with integration of different levels of medical facilities, governmental sectors and non-governmental community resources, the diabetes shared care model is feasible in Taiwan. Through its implementation, quality of regional diabetes care has achieved preliminary improvement.