In Singapore, chronic care is provided by both ambulatory primary care clinics and specialist clinics in hospitals. In 2005, the National Healthcare Group (NHG) embarked to build a diabetes registry to enhance the continuity of care for patients with diabetes and facilitate greater efficiency in outcome measurement. This Chronic Disease Management System (CDMS) links administrative and key clinical data of patients with diabetes mellitus across the healthcare cluster. At the point of patient care, clinicians view a summary of each patient's chronic disease records, consolidated chart with physical parameters, laboratory investigation results and the "patient reminders" listing the clinical decision support prompts when key laboratory and screening tests are due for each patient. The CDMS provides reports of clinical outcomes in a systematic and efficient manner for quality improvement and evidenced-based population management. These include process indicators consisting of the rates of glycated haemoglobin (HbA1c), low-density lipoprotein-cholesterol (LDL-c) and nephropathy tests; and intermediate outcome indicators of the proportion of patients with poor HbA1c (>9%) and optimal LDL-c (<2.6 mmol/L) control. From January 2007 to December 2008, the rates of the 3 process indicators were relatively unchanged and that of HbA1c and LDL-c tests were high. There was gradual improvement in the proportion of patients achieving target level of LDL-c in both primary care clinics and hospitals. Fewer patients at primary care clinics had poorly-controlled HbA1c. As a tool for chronic care delivery, the NHG diabetes registry has made clinical monitoring and outcome management for patients with diabetes mellitus more efficient.