Introduction The prevalence of Diabetes Mellitus in Sri Lanka is increasing. We describe the characteristics of patients with optimal and suboptimal control of diabetes among known diabetics in a 35–64-year-old urban population resident in the Ragama Medical Officer of Health (Ragama MOH) area of Sri Lanka.

Methods A cross sectional study was conducted among 2986 randomly selected 35–64 year olds in the Ragama MOH area from January to September 2007. A detailed history was taken and participants were subjected to a physical examination and assay of fasting blood glucose and HbA1C. A HBA1C <6.5 was taken as evidence of optimal control.

Results There were 474 persons (194 males and 280 females) who gave a past history of diabetes. 9 males and 9 females were not on any treatment. 27 persons (9 males and 18 females) were on insulin. Of the 474 diabetics, 113 (48 males and 65 females) had a HbA1c <6.5. The average fasting blood glucose of diabetics with optimal control was 120+21 mg/dl. The mean fasting blood glucose level of the 361 subjects with sub optimal control was 190+70 mg/dl. Optimal glycaemic control was not associated with alcohol intake, smoking, obesity, central obesity and low physical activity levels.

Conclusions Most known diabetics had access to treatment but only approximately 25% were optimally treated. The need to optimally manage these patients is highlighted.