Background: Renal ischemia-reperfusion (IR) injury is a frequent cause of acute kidney injury, which results in high morbidity and mortality. Inflammation is an important factor that is involved in kidney repair after renal IR injury. IL-10 is a potent anti-inflammatory cytokine that inhibits inflammatory pathways, but the role of IL-10 in repairing renal IR injury is not known. Here, we investigated the role of IL-10 in kidney repair after renal IR injury. Methods: We used an IL-10<sup>-/-</sup> mouse model and examined the serologic and histomorphology of kidney after IR injury. We also measured ki67, TNF-α, IL-6, and macrophages with immunohistochemistry or Western blotting. Results: There was a greater increase in serum creatinine in IL-10<sup>-/-</sup> mice than in wild-type (WT) mice. And compared with WT mice, IL-10<sup>-/-</sup> mice had increased histologic renal injury and decreased proliferation. Moreover, the expression of TNF-α, IL-6 and macrophages was clearly increased in IL-10<sup>-/-</sup> mice compared with the WT mice. Conclusion: These data reveal an important role for IL-10 in the improvement of renal IR injury, acting through suppression of inflammatory mediators, and that IL-10 would be a crucial target for the treatment of IR injury.