Oxidative stress arises when the host defensive mechanisms of anti-oxidants cannot withstand the fierce attack launched by numerous reactive oxygen and nitrogen species. This prooxidant-antioxidant imbalance can cause endocrine, cardiovascular, pulmonary, and neurological disorders. In sepsis, this imbalance promotes organ failure, including bone marrow. The aim is to evaluate the anti-oxidant effect of montelukast compared with dexamethasone against LPS-induced oxidative stress in bone marrow. For this purpose, twenty-eight male Albino mice were randomly assigned to four groups of seven per each. Group I (control) received distilled water by oral gavage once a day for a week and euthanised on the 8th day; Group II (induction) received a single intraperitoneal injection of LPS 10 mg/kg and euthanised on the 2^nd day. Group III received oral gavage dexamethasone 2.5 mg/kg once a day for a week, then two hours after the final dose, LPS was given and euthanised on the 8^th day. Group IV received oral gavage montelukast 20 mg/kg once a day for a week, then two hours after the final dose, LPS was given and euthanised on the 8^th day. Results showed that the LPS-model group had significantly higher malondialdehyde and myeloperoxidase levels than the control group. Pretreatment with dexamethasone (group III) and montelukast (group IV) significantly lowers both values. In bone marrow histopathology, montelukast reduced inflammatory cells without affecting red blood cells. In conclusion, Montelukast may be a promising anti-oxidant and a medication to prevent terrible oxidative stress results in humans.