Sildenafil citrate has shown to display beneficial cardiovascular effects, suggesting that it may have other systemic benefits involving the endothelium. There is little data regarding the long-term use of this drug and the effects of this on different organs. Objective: The primary aim of this study was to determine whether sildenafil citrate diminishes concentrations of microalbuminuria and percentage of Ale in patients with type 2 diabetes. Design: A double-blind, randomized, controlled trial in 40 male patients, age 35-50, with type 2 diabetes. Subjects received sildenatil citrate 50 mg daily (n = 20) or placebo (n = 20) for 30 days. Levels of hs-CRP, rrticroalbuminuria, homocysteine, Ale and erectile function were measured at baseline and to the end of the study. Results: Men that received sildenafil citrate displayed a significant decrease in the microalbummuria concentrations (p < 0.01) versus baseline, (p = 0.02) versus placebo and Ale (p < 0.01) versus baseline, (p = 0.01) versus placebo. In addition, we observed a significant increase in the total IIEF score after 30 days of treatment (p < 0.01) versus baseline, (p < 0.01) versus placebo. Conclusions: The administration of 50 mg of sildenafil citrate for 30 consecutive days diminishes microalbuminuria and the percentage of Ale in patients with type 2 diabetes. (C) 2007 Elsevier Ireland Ltd. All rights reserved.