Cyclophosphamide (CP) is a drug with a wide spectrum of clinical uses. It has a potent effect in treatment of many types of cancers. CP adverse side effects limit its therapeutic uses. Renal damage is one of the limiting side effects of CP. Recently; ozone therapy (OT) has important clinical effects in minimizing the renal injury. Thus, the aim of our study was to investigate whether ozone has potency to reduce the adverse toxic effects of cyclophosphamide in rat kidney. Methods: Forty male albino rats were divided in five groups: Control (C), cyclophosphamide –induced nephrotoxicity (CPIN) injected I.P. with a single dose 200mg/kg CP. Two groups treated with CP in pre- or post-treatment of ozone therapy PRO/POO; respectively and the fifth group is ozone- only treated group (OT- only), rats treated with a single I.P. dose of ozone/oxygen mixture (0.7 mg/kg). Serum and kidney tissues used to evaluate the urea and creatinine levels, histopathological examinations, oxidative stress parameters and pro-inflammatory cytokines expressions. Results: The results showed that CP administration caused damage in the kidney after 24 h with significant decrease in total glutathione (tGSH), super oxide dismutase (SOD) and increased in lipid peroxidation (MDA) and nitric oxide (NO) values. In line with elevations in the serum (TNF- alpha) and (IL-6). The results showed improvement in PRO group but no changes in POO group compared to the CPIN group results. Conclusions: The study represents that pre-treatment of ozone decreased the renal severity of CP in a manner leading to modulations in kidney histopathology alterations.