Exercise, alone or combined with changes in lifestyle, can prevent or reduce the need for pharmacotherapy in patients with compromised endothelium-dependent function. The aim of this study was to examine the protective effect of aerobic exercise against (L-NAME)-kidney damage in male rats induced by Nω-nitro- L-arginine methyl ester (L-NAME). L-NAME was administered to rats intraperitoneally in doses of 10 mg kg-1 six days a week over eight weeks. Rats exercised by running on a treadmill at the speed of (15 to 22) m min-1, 25 min to 64 min per day, five days a week over eight weeks. The rats were killed 48 h after the last dose, and their kidneys removed and homogenised to measure the levels of heat shock protein70 (HSP70), superoxide dismutase activity (SOD), and thiobarbituric acid reactive substances (TBARS). We also measured serum nitrite/nitrate. Chronic administration of L-NAME significantly increased renal HSP70 and TBARS levels and decreased renal SOD activity and serum nitrites/nitrates. Training modified abnormal renal HSP70, lowered TBARS, and increased SOD and serum nitrite/nitrate. Our results have confirmed that regular aerobic exercise protects against nitric oxide deficiency-induced kidney damage by modifying HSP70, up-regulating SOD activity, and depleting TBARS.