Abstract: The nephroprotective and diuretic effects of three medicinal herbs namely Petroselinum sativum, Eruca sativa and Curcuma longa, alone and in combination, against gentamicin (GM)-induced nephrotoxicity in rats were investigated. Forty two adult male Sprague Dawley rats were randomly distributed into 6 equal groups, each of 7 animals. The 1st group was injected intraperitoneally (i.p.) with saline solution (0.2 mL/rat). The 2nd group was i.p., injected with GM (80 mg/kg b.wt.) for 8 consecutive days. The other four groups were given orally aqueous infusion of the three herbs, alone and combined, (1 mL/rat, 150 mg/kg b.wt.) along with GM. Twenty four hours after the last administration, blood and urine samples were taken for biochemical analyses. Kidney specimens were taken for estimating oxidant/antioxidant parameters and for histopathology. The results showed that GM induced nephrotoxicity characterized by renal dysfunction as evident by biochemical and histopathological alterations, elevated lipid peroxidation and reduced activity of antioxidant enzymes in kidney tissues. Oral administration of aqueous infusion of Petroselinum sativum, Eruca sativa and Curcuma longa herbs caused a nephroprotective effect evident by significant decreases in the elevated serum urea, creatinine and ALP activity and normalized the decreased serum levels of Na+ and K+ electrolytes in GM-treated rats. It significantly increased urine output and urinary concentration of Na+and K+; denoting a diuretic activity. It also ameliorated renal tubular necrosis in GM-treated rats. The nephroprotective of herbs could be due to the antioxidant effect of these herbs as evident by increasing activity of antioxidant enzymes. Conclusively, the study suggests that mixture of these three herbs may be useful for patients who suffer from renal diseases and those on GM therapy.