Introduction: To investigate the effect of the tadalafil in experimental renal I/R injury and to evaluate these changes with IMA (nonspesific early biomarker of ischemia), NO and MDA levels. Materials and methods: Twenty four female Wistar rats were randomly divided into 3 groups (n=8): Group I, sham; Group II, 60 min I/R; Group III, 60 min I/R plus tadalafil. Tadalafil was administered via an orogastric tube (10 mg/kg) 24 h prior to the procedure. After ischemia of the left kidney and 1 h of reperfusion, blood samples were obtained, and the kidney was removed. Results: Statistically significant histopathologic changes were exist between groups, with the most severe injury was determined in group II in comparison to the others (X-2=21,803, P=0.000). Also mean serum IMA levels were higher in group II, but not statistically significant (19.83 +/- 7.81 U/ml, 22.26 +/- 7.14 U/ml and 19.82 +/- 7.77 U/ml, P=0.613). In addition, NO values were lower in I/R groups (P=0.049). There were no differences among the groups in terms of MDA. Conclusions: IMA may be used as a nonselective biomarker for IR injury before the occurrence of necrosis. Decreased IMA levels may indicate the nephroprotective effect of tadalafil in renal IR injury.