The main aim of the present study was to evaluate short-term effects of Lovastatin Therapy on proteinuria of type 2 diabetic nephropathy. This was a quasi clinical trial with treatment and withdrawal periods carried out at Drug Applied Research Center of Tabriz University of Medical University. Men with clinically documented T2DN were enrolled. To eliminate potential confounding factors, we only included patients with type 2 diabetes mellitus and proteinuria levels lower than the nephrotic range (< 3 g/d) whose estimated glomerular filtration rate (eGFR) was higher than 30 mL/min/1.73m2. The plasma glucose and blood pressure of the participants was controlled by standard drugs lacking confounding effect when needed. All of the patients were under their own regular restricted protein diet. Exclusion criteria included: the use of 3-hydroxy-3-methylglutaryl coenzyme A antagonists, fibrates, aspirin, β-blockers, allopurinol, vitamins, pentoxifylline, fish oil, other antioxidant drugs consumed in the previous three months, active smoking, chronic inflammation, active coronary artery disease in the previous three months (diagnosed by symptoms and electrocardiography), and poorly controlled diabetes mellitus. Samples were drawn before lovastatin therapy (of 20 mg/d; Ghazal Co, Tehran, Iran), after 45 days of lovastatin therapy, after 90 days of lovastatin therapy, and 30 days after the withdrawal of lovastatin therapy. Serum cratinine (Cr) and urea were determined using standard methods. eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) formula. Twenty-four hour urine samples, Cr, and protein levels were assessed using coulorimetric and immunoturbidimetric methods.