In the present study, effect of olive (Olea europaea L.) leaf extract, known for its antioxidant quality, on ischemia/reperfusion (I/R)-induced injury in the kidney was investigated. A total of 3-4-month-old, weighing 200-250 grams each Spraque Dawley rats were divided into four groups (n=7): Group I (Sham), Group II (I/R+physiological saline solution), Group III (I/R+100 mg/kg of olive leaf extract), Group IV (I/R+200 mg/kg olive leaf extract). A right kidney nephrectomy surgery was conducted to all groups under anesthesia. After 15 days of healing process physiological saline solution was orally given to the rats in Group I and II; olive leaf extract was given to Group III and IV. Forty five minutes ischemia and 24 hours reperfusion was conducted on all rats except those in Group I. At the end of the experiment, Blood Urea Nitrogen (BUN), Creatinine (CRE), and Uric Acid (UAC) values; and Superoxide Dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Cathepsin B and Cathepsin L enzyme activities and Malondialdehyde (MDA) levels were investigated. The results revealed that 200 mg.kg(-1) of olive leaf extract have a protective effect against oxidative stress damage caused by renal I/R.