Objectives: The aims of the study were to estimate the prevalence of diabetes in Luxembourg in 2002, to compare it to the prevalence reported in 1991 and to evaluate if prescription attitudes have changed since 1991., Methods: The prevalence of diabetes was estimated using the drug sales data. The key parameters, total amount of antidiabetic drugs sold in one year and the average daily dose or Prescribed Daily Dose (PDD), have been obtained from the National Social Security Organization and by a standardized questionnaire sent to all general practitioners and all internists and endocrinologists of the country., Results: The PDD was calculated on 2,402 questionnaires on individual diabetic patients. By this mean, the proportion of patients only treated with appropriate diet could also be obtained. Compared to 1991, the total amount of antidiabetic drugs showed a four-fold increase in biguanides tablet prescriptions. A high percentage of combined treatments was found. The prevalence of diabetes in Luxembourg was found to be 3.05% of the total population., Conclusions: Compared to the status in 1991, prevalence of diabetes increased by 63%, which seems mainly due to type 2 diabetic patients as orally-treated diabetic patients almost doubled (2.11% vs 1.16%). A substantial change in prescriptions for diabetes has occurred, suggesting a positive influence of studies like the United Kingdom Prospective Diabetes Study (UKPDS).