Objective: To compare the effect of complete and partial renal capsulotomy on the renal function tests and oxidative stress markers in rats undergoing ischemia-reperfusion injury. Design: Randomized controlled experimental study. Animals: A 60 Spraque-dawely rats weighing 180 ± 50 g. Procedures: Rats were divided into 3 groups in triplicate (6 each). In addition, 6 rats were subjected to blood and renal tissues sampling for estimation of normal parameters. Group 1 (Positive control): ischemia reperfusion (IR) injury; Group 2: Complete capsulotomy + I R; Group 3: Partial capsulotomy + IR. Six rats from each group were sacrified at 2, 7 and 14 days post- surgery. Results: The complete capsulotomy induced a significant decrease in the serum creatinine at 2 and 7 days post- capsulotomy in comparison with partial capsulotomy (P < 0.05), whereas at 14 days, the partial capsulotomy induced the significant decrease (P < 0.05). Complete capsulotomy showed a significant improvement in creatinine clearance in comparison with partial capsulotomy at 2, 7 and 14 days post- surgery (p < 0.05). At 2 and 7 days, BUN of IR+ Capsulotomy group showed a significant decrease (P < 0.05) compared to the other groups, while at 14 days partial capsulotomy, the serum BUN reached to the normal value. Serum sodium level showed a significant decrease (P < 0.05) at 2 days after partial capsulotomy, and at 14 days after complete capsulotomy (P < 0.05). Nitric oxide level in IR + partial capsulotomy group showed a significant decrease at 7 and 14 days (P < 0.05). Results of MDA of IR+ partial capsulotomy groups showed a significant decrease (P < 0.05) compared to the IR+ compete capsulotomy groups at 2,7 and 14 days. Conclusion and clinical relevance: The partial capsulotomy ameliorates could improve serum creatinine, BUN and could lower the oxidative stress at 14 days. Partial capsulotomy could also improve the renal tissues at both short and long-term. So this study indicates the importance of the presence of intact renal capsule for ischemic acute kidney injury