Objective: To update prevalence data on pharmacologically treated diabetes in France (excluding Mayotte) in 2012 and to describe regional disparities. Methods: People with diabetes receiving treatment, across all health insurance schemes, are identified in the National Inter-Scheme Health Insurance Information System (Sniiram) based on the dispensing of oral antidiabetic medications or insulin on at least three different dates during the year (two if at least one large package is dispensed). Analysis of diabetes prevalence by department/region of residence and across five zones defined based on quintiles of a social deprivation index calculated at the municipal level (Q1—least deprived quintile to Q5—most deprived quintile) allows for an understanding of regional disparities. Results: The prevalence of pharmacologically treated diabetes reached 4.6% in 2012. Over the 2010–2012 period, the average annual growth rate was 2.5%. High prevalence rates were confirmed in the overseas departments, in the northern and northeastern regions of mainland France, and in Seine-Saint-Denis. In 2012, the prevalence of treated diabetes increased in line with the territorial social disadvantage index, among both women and men. Prevalence ratios were slightly higher among women, particularly in the most disadvantaged areas (Q5/Q1: 1.7 among women and 1.3 among men). Conclusion: The prevalence of pharmacologically treated diabetes continues to rise. It is essential to continue primary prevention efforts aimed at reducing its main modifiable risk factors (overweight, obesity, sedentary lifestyle) and to implement policies tailored to at-risk populations, particularly the most disadvantaged. (R.A.)