BACKGROUND Recently it has been demonstrated that hydrogen, as a novel antioxidant, can selectively reduce hydroxyl radicals (·OH) and peroxynitrite anion (ONOO-) in vitro and exert therapeutic antioxidant activity in many diseases. This study was designed to investigate the effect of hydrogen-rich saline on renal ischemia/reperfusion (I/R) injury in rats. METHODS A rat model of renal I/R injury was induced by 45-min occlusion of the bilateral renal pedicles and 24-h reperfusion. Physiologic saline, hydrogen-rich saline, or nitrogen-rich saline (8 mL/kg) were administered intraperitoneally at 5 min before reperfusion, respectively. RESULTS After I/R injury, serum blood urea nitrogen (BUN), creatinine (Cr), tissue malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OhdG), TNF-α, IL-1β, IL-6 levels, and myeloperoxidase (MPO) activity were all increased significantly, while tissue superoxide dismutase (SOD) and catalase (CAT) activities were all decreased significantly. Hydrogen-rich saline reversed these changes and relieved morphological renal injury and I/R-induced apoptosis, while no significant changes were observed in the nitrogen-rich saline-treated group compared with physiologic saline-treated group. CONCLUSIONS Hydrogen-rich saline is able to attenuate the renal I/R injury, which is possibly by reduction of oxidative stress and inflammation.