The occurrence of non-diabetic renal disease (NDRD) in diabetic patients is well established, with different frequencies from all around the world. We report 13 cases of isolated NDRD in diabetic patients diagnosed in our unit and present our biopsy criteria in these patients. From January 2000 to December 2008, 13 diabetic patients with suspected NDRD underwent renal biopsy. The case records of these patients were retrospectively analysed. Nine were males and the mean age was 51 years (10-75). Two had a type I diabetes and 11 had a type II diabetes. The mean duration of diabetes was 36 and 30 months in type I and II respectively. Indications for renal biopsy included: absent retinopathy in 11 cases (84%), heavy proteinuria in four cases (30%), acute renal failure (ARF) in three cases (23%), rapidly progressive renal failure (RPRF) in one case (7%), hematuria in five cases (38%), extra-renal signs in four cases (30,7%), short duration of diabetes in all cases. In conclusion, NDRD was observed in our study in patients with a short duration of diabetes and atypical clinical or biological findings.