Purpose: To determine the protective effect of aliskiren on ischemia-reperfusion (I/R) injury in a rat renal (I/R) model. Methods: Rats were randomly divided into five groups: sham control group; sham control with aliskiren pretreatment; I/R group and I/R with two doses of aliskiren pretreatment. Rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 24 h reperfusion. Aliskiren (50 and 100 mg/kg) was administered orally by gavage 24 and 1 h prior to ischemia. After 24 h reperfusion, kidney samples were taken for the determination of malondialdehyde (MDA) level, superoxide dismutase (SOD), glutathione (GSH) activity and histological evaluation. The level of serum creatinine (SCR) and blood urea nitrogen (BUN), renin and angiotensin II (AT-2) was measured in serum samples. Results: Kidneys from I/R groups showed significant increase in MDA level and significant decrease in GSH, and SOD activity. IL-1 beta, iNOS and NF kappa B gene expression significantly increased in the I/R groups in the rat kidney tissue. Aliskiren treatment showed a significant down-regulatory effect on IL-1 beta, iNOS and NF kappa B mRNA expression. Compared with the sham group, SCR and BUN, renin and AT-2 were significantly increased in the I/R rats, accompanied by histopathological damage to the kidney. Conclusion: Pretreatment with aliskiren ameliorated I/R-induced renal injury through decreasing nitric oxide and AT-2 levels and by the reduction of injury induced by I/R injury and ameliorated renal histopathological molecular and biochemical changes.