There is substantial heterogeneity regarding diabetes mellitus prevalence and glycemic control in Asian populations. The authors examined a population-based sample of 3000 adults (52% women) of Malay ethnicity (40-80 years) in Singapore. The age-standardized prevalence of diabetes mellitus was 18.4% (95% confidence interval = 17.0% to 19.8%). Being overweight, presence of hypertension, presence of cardiovascular disease, and family history of diabetes were found to be positively associated with diabetes mellitus. Higher education, employment status, and current smoking were found to be inversely associated with diabetes mellitus. Among those treated for diabetes, 29% achieved the optimal glycemic goal (glycosylated hemoglobin <7%). Lower levels of low-density lipoprotein cholesterol, total cholesterol, and systolic and diastolic blood pressure were associated with good glycemic control. Nearly 1 in 5 middle-aged Malay adults living in a developed Asian society had diabetes mellitus and a substantial proportion had suboptimal glycemic control.