Background: Diabetic nephropathy is the most prevalent cause of end stage renal disease (ESRD). Besides, factors such as angiotensin-II, cytokines, and vascular endothelial growth factor (VEGF), uric acid may play a role as the underlying cause of diabetic nephropathy. Therefore, decreasing serum level of uric acid can be effective in treatment of diabetic nephropathy. Methods: This was a double-blinded, randomized, clinical trial in which 40 patients with type 2 diabetes mellitus (DM) and diabetic nephropathy with proteinuria (at least 500 mg/24h) and serum creatinine (Cr) level 0.05). Serum level of uric acid and 24 hour urine protein were significantly lower in control group, after four months of receiving allopurinol, compared with control group (P < 0.05). Conclusion: Low dose allopurinol (100mg/day) reduces severity of proteinuria after four months of taking, which is probably due to decreasing the serum level of uric acid. So, allopurinol can be administered as an adjuvant, cheap, and low side-effect therapy for patients with diabetic nephropathy
