Abstract Type 2 diabetic nephropathy may be the consequence of some non-diabetic form of renal disease, unlike type 1 diabetes mellitus (DM) of long duration (≥10 years) in which severe proteinuria is always related to a well -defined pattern of diabetic nephropathy. The clinical manifestations of diabetic nephropathy are similar in type 1 and type 2 diabetes, while the renal lesions may differ. Diabetic glomerulopathy is the predominant renal lesion in type 1 diabetes, although tubular, interstitial and arteriolar lesions are also present in the advanced stages of renal disease. In contrast, in type 2 diabetes renal lesions are heterogeneous and several patients who fall into this category and who also suffer from diabetic kidney disease have mild or absent glomerulopathy with tubulointerstitial and/or arteriolar abnormalities. In addition, a high prevalence of non-diabetic renal diseases (NDRD), isolated or superimposed on classic diabetic nephropathy lesions have been reported in patients with type 2 diabetes, often reflecting the bias of selecting patients for unusual clinical presentations for renal biopsy. In this case report is illustrated that the nephrotic syndrome in patients with diabetes mellitus is not always associated with diabetic nephropathy non-diabetic renal disease.