The aim of this retrospective study was to evaluate the prevalence of microalbuminuria in type 1 and 2 diabetic patients with or without high blood pressure levels. 653 patients were involved in the study [type 1: n = 413 (normotensive: n = 298; hypertensive: n = 115); type 2: n = 240 (normotensive: n = 93; hypertensive: n = 147)]. In type 1 diabetic patients, the prevalence of microalbuminuria was of 21 per cent. Microalbuminuria was also found in 28 per cent of type 2 diabetic subjects (p less than 0.10 vs type 1). The prevalence of microalbuminuria was significantly higher in hypertensive than in normotensive diabetic subjects (28 vs 20 per cent; p less than 0.05). Blood pressure in type 1 and 2 normotensive patients was significantly higher in subjects with than without microalbuminuria. We also observed higher HbA1 levels in microalbuminuric type 1 diabetic patients. Finally, we also assessed that the prevalence of diabetic chronic complications was higher in type 1 patients with than without microalbuminuria (p less than 0.05). This relationship was not evidenced in type 2 diabetic patients. In conclusion, the prevalence of microalbuminuria in a population of type 1 and 2 diabetic patients is high. We confirm in this study the relationship between microalbuminuria, blood pressure, and HbA1.