The prevalence of cancer, in the world is increasing steadily. Despite intense research efforts, no approved therapy is yet available. Cisplatin is a chemotherapeutic drug but induces acute tissue injury. Oleuropein (OLE) is a major phenolic compound and used as a possible natural antioxidant, antimicrobial, and anticancer agent. We hypothesized that antioxidant activity of OLE may decrease cisplatin-induced oxidative stress and prevent to the development of chemotherapeutic complications including abnormality in hematological condition. Male Sprague Dawley rats were used in the experiments. Rats were randomly assigned to one of eight groups: control group; group treated with i.p. injection in a single dose of 7 mg/kg/day cisplatin; groups treated with 50, 100 and 200 mg/kg/day OLE (i.p.); and groups treated with OLE for 3 days starting at 24 h following cisplatin injection. First, hematological assessment was appreciated between control and experimental groups. Second, total oxidative stress (TOS) and total antioxidant capacity (TAC) levels of blood were measured by biochemical studies. In addition to this, oxidative DNA damage was determined by measuring as increases in 8-hydroxy-deoxyguanosine (8-OH-dG) adducts. The treatment with cisplatin elevated the TOS and 8-OH-dG levels that were then reversed by OLE. Reductions in antioxidant capacity with respect to corresponding controls were also restored by OLE treatment. These findings suggest that the OLE treatment against cisplatin-induced toxicity improves the function of blood cells and helps them to survive in the belligerent environment created by free radicals.