Cyclophosphamide (CP) is a drug used in the treatment of diseases such as cancer and rheumatoid arthritis, and its use is limited because it causes side effects such as various organ damage, bone marrow toxicity, and hematopoietic dysfunction. In this study, it was aimed to investigate the protective effects of olive leaf extract (ZYE) against anemia in rats. The study period was 28 days. For this purpose, CP was administered at a dose of 50 mg/kg once a week intramuscularly in the group in which anemia model was created. In the treatment group, 400 mg/kg ZYE was administered by oral gavage method. At the end of the study, red blood cells (RBC), white blood cells (WBC), hemoglobin concentration (HGB), hematocrit value (HTC), mean red blood cell hemoglobin (MCH), mean red blood cell volume (MCHC) and red blood cell distribution (RDW) were determined. In serum samples, malonyldialdehyde (MDA) and reduced glutathione (GSH) levels, catalase (CAT) and glutathione peroxidase (GSH-Px) enzyme activities were analyzed by spectrophotometric method. It was determined that CP administration caused statistically significant decreases in blood RBC (P<0.01), HGB (P<0.001) and HTC (P<0.001) parameters. In addition, it was determined that this application caused an increase in serum MDA (P<0.05) level, a decrease in GSH (P<0.05) level and CAT (P<0.05) and GSH-Px (P<0.01) enzyme activities, resulting in oxidative stress. It was determined that olive leaf extract treatment prevented the oxidative damage caused by CP, also prevented the decrease in RBC, WBC, HGB and HTC values and showed protective effects against anemia.