There were no studies on the different stages of diabetic nephropathy in Saudi Arabia, particularly the earliest stages. We have therefore investigated the frequency of occurrence of varying degrees of proteinuria including microalbuminuria in noninsulin-dependent diabetes mellitus (NIDDM) Saudi patients as well as the correlation of varying degrees of proteinuria with other diabetic complications and risk factors. One hundred and twenty-five NIDDM patients were studied. Fifty-seven were males and 68 were females. Their mean age was 49.8 +/- 10 years with a mean duration of diabetes of 9.48 +/- 6 years. The mean of HbA1c was 10.3 +/- 2.6%, serum creatinine was 76.7 +/- 23 mmol/L, creatinine clearance 94.3 mL/min, glomerular filtration rate 129.7 +/- 44 and effective renal plasma flow was 496.5 +/- 153. The pattern of proteinuria group was as follows: nephrotic range proteinuria 5.6%, clinical proteinuria 30.4%, microalbuminuria 16.8%. Hypertension and retinopathy were present in 36.8% and 37% of the patients respectively. A significant correlation was found between the presence of hypertension, duration of diabetes and development of diabetic nephropathy. Similarly, a significant correlation was found between retinopathy and the degree of proteinuria. In conclusion, the pattern of diabetic nephropathy in the Saudi NIDDM patients is similar to that in the Western world. Hypertension and duration of diabetes mellitus are important risk factors in the development of diabetic nephropathy. There is a good correlation between retinopathy and the degree of proteinuria.