OBJECTIVES: To study the prevalence of renal failure in a large sample of type 2 diabetes patients in Belgium and to compare the results with the data of the Belgian ESRD registry. METHODS: A total of 5355 patients, 2530 males and 2825 females, suffering from type 2 diabetes and treated with oral antidiabetic drugs were recruited from the patient files of 345 Belgian general practitioners. Age, gender, body height, body weight, and serum creatinine were recorded. Renal function was calculated using a BMI-corrected Cockroft-Gault formula and the abbreviated MDRD formula. Annual incidence of diabetics starting renal replacement therapy was retrieved from the Belgian national ESRD registry and diabetes prevalence data from the Scientific Institute of Public Health. RESULTS: The mean age was 68 years in females and 64 years in males. The mean body weight was 76.01 kg in females and 84.64 kg in males. The mean serum creatinine was 1.04 mg/dl (range: 0.5-3.0 mg/dl) in females and 1.14 mg/dl (range: 0.5-10.2 mg/dl) in males. Serum creatinine levels had a tendency to rise, both in females and males, from the age of 60 years. Renal function showed a tendency to decrease with age, regardless of the method of calculation. If we compare these results with those found in a Belgian study of the general population, we observed that the 3rd percentile of the renal function estimate in diabetics was almost identical to that of the general population. The annual incidence of ESRD among diabetics type 2 is 23 per million inhabitants. Given a prevalence of diabetes of 2.6%, the annual incidence of ESRD can be calculated as 0.088 %. CONCLUSIONS: Apparently, there is no excess renal failure in the diabetes population and the decrease in renal function with advancing age is identical in both populations. ESRD among diabetics type 2 is rare.