OBJECTIVE: Level of serum HOMOCYSTEINE is remarkably common among patients with moderate to sever renal failure. We assessed whether serum HOMOCYSTEINE concentrations were correlated with proteinuria in overt diabetic nephropathy.MATERIALS AND METHODS: A cross-sectional study was carried out on 45 patients (29 males, 16 females) with overt proteinuria. All subjects had type 2 diabetes. Data included age, sex, hypertension, serum creatinine, creatinine clearance, 24-hour urine proteinuria, lipid profiles and serum HOMOCYSTEINE.RESULTS: The mean of serum HOMOCYSTEINE concentrations was 18±7.7 mmol/L (4.6-42), having 31 (70%) hyperHOMOCYSTEINEmia. The mean of 24-hour urine proteinuria was 1515±996 mg, for serum creatinine 1.9±0.7 mg, and for creatinine clearance, it was 97±26.6 mL/min. Serum HOMOCYSTEINE had a negative correlation with creatinine clearance (r=-0.4, p=0.007) and revealed no correlation with 24-hour proteinuria (p=0.9).CONCLUSION: In overt nephropathy in diabetes type 2, patients with higher HOMOCYSTEINE had lower creatinine clearance. However, there was no correlation between HOMOCYSTEINE and overt proteinuria.