Extrapolating from the results of the 1998 and 2000 French National Sickness Insurance Fund surveys, it can be estimated that at the end of 2002, 3.4% of the French population, i.e. 2,150,000 individuals, had diagnosed type 1 or type 2 diabetes mellitus. Among these individuals, 2,050,000 were taking drug treatments and about 100,000 were treated with diet alone. About 16.3% of diabetics given drug treatments were taking insulin, alone or in combination with oral antidiabetic drugs, i.e. approximately 447,000 individuals including 316,000 (70.6%) with type 2 diabetes. Regarding all individuals with type 2 diabetes, the percentage treated with insulin (alone or in combination with oral antidiabetic drugs) increased from 12.3% in 1998 to 16.5% in 2002, for a mean increase of 7.4% per year. This rate is globally corroborated, although the study periods are not exactly comparable, by changes in sales volumes for insulin observed over recent years showing an even more rapid mean annual growth of 13.4%. The difference between these two estimates suggests that either the mean dose of insulin delivered is increasing or that the increase in the number of treated diabetics is underestimated by the National Sickness Insurance Fund. Mean age of patients treated with insulin alone (type 1 and type 2 diabetics considered together) was 56.3 years with a median of 60 years and a sex ratio (M/F) close to 1 (0.9). There are no national data detailing monitoring practices in insulin-treated patients. Published analyses focus on type 2 diabetics treated with oral antidiabetic drugs and often exclude patients taking insulin. Blood glucose control is poor (HbA1c>8%) in approximately one-third of patients with type 2 diabetes and different studies have shown that in France among subjects with type 2 diabetes 3.1% are taking two oral antidiabetic drugs or more at maximal doses and have poorly controlled blood glucose levels. The percentage of insulin-treated diabetics is increasing steadily, but remains lower than observed in other European countries (generally reported in the 24% to 30% range). This special situation in France could fade out in upcoming years with better awareness of the importance of metabolic control, improved insulin therapy in this context, and improved conditions for use of insulin.