Background Osteoporosis is the most common skeletal disorder and is considered a risk of fracture. Most medication used for the treatment of osteoporosis is antiresorptive; however, strontium ranelate (Sr) therapy in postmenopausal women has shown a double effect on resorption and bone formation. In this study, the effect of Sr on status of the oxidative stress and antioxidant defence system was investigated. Methods Twenty-one adult albino female Wistar rats were used. The animals were randomly assigned into three groups, control (sham operated rats, received saline), OVX (ovariectomized rats), OVX + Sr (4 months later ovariectomy, strontium ranelate treatment was begun and continued for 120 days) each containing 7 animals. Strontium ranelate (500 mg/kg/day) and placebo (saline) were administered via oral gavage. At the end of the treatment, liver and kidney of rats were removed and malondialdehyde (MDA) level, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were determined by biochemical analysis methods. Results In liver, MDA levels were significantly higher in the OVX and OVX + Sr groups than the control group. GSH-Px activity decreased in OVX group and increased in OVX + Sr group compared with values of control group. CAT activity was increased in the OVX + Sr group when compared to control group. In kidney, MDA level was increased in OVX group. SOD activity was decreased in the OVX + Sr group. GSH-Px activity decreased in OVX group and increased in OVX + Sr group compared with control group.CAT activity increased in the OVX + Sr group when compared to control. Conclusion According to our results, Sr has preventive effect on oxidative damage in ovariectomized rats.