The role of the tumor necrosis factor (TNF)-α in the pathophysiology of renal ischemia/reperfusion (I/R) injury is unclear. We investigate the effects of TNF-αR1 gene deletion and infliximab administration on the degree of renal injury induced by I/R. TNF-αR1 knockout (TNF-αR1KO) and wild-type (TNF-αWT) mice were subjected to bilateral renal artery occlusion (30min) and reperfusion (24h). Infliximab (10mg/kg subcutaneously, s.c.) was administered 1h before ischemia. At the end of experiments, urea, creatinine, γGT, and AST were measured to assess renal function and reperfusion injury. Markers of oxidative stress, pro-inflammatory mediators, iNOS, COX-2, and NF-κB signaling pathway were measured. Kidney myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels were measured to study polymorphonuclear cell infiltration and lipid peroxidation. TNF-αR1 gene deletion and infliximab administration prevented the increase of urea, creatinine, γGT, kidney AST levels, iNOS and COX-2 expression, NF-κB translocation, MPO activity and MDA levels. TNF-αR1 gene deletion and infliximab administration lowered the histological evidence of renal damage associated with I/R and caused a reduction of nitrotyrosine suggesting reduced nitrosative stress. Our results demonstrate that TNF-α plays an important role in I/R injury and put forward the hypothesis that modulation of TNF-α expression may represent a novel and possible strategy.