Objectives: Hepatotoxicity is a severe outcome of methotrexate (MTX) therapy, limiting its clinical use and contributing to its related morbidity and mortality. This study investigated the hepatoprotective effects of nitazoxanide (NTZ), anantiprotozoal drug, against MTX-induced hepatotoxicity and whether endoplasmic reticulum (ER) stress modulation underlies the expected beneficial effects of NTZ. Methods:Thirty-six rats wereallocated to six groups, one controlgroup and fiveMTX groups, whereinduction of hepatotoxicity was achieved via injecting MTX (20 mg/kg). Groups were assigned as MTX-vehicle, NTZ-100, and NTZ-200 groups (at 100 and 200 mg/kg/day, gavage, respectively), N-acetyl cysteine (NAC) group (500 mg/kg), and 4-phenyl butyric acid (4-PBA) group (150 mg/kg, i.p). Liver function enzymes in serum, hepatic oxidative stress, proinflammatory cytokines, apoptosis, and ER-stress biomarkers were assessed. A histopathological examination was performed. Results: Treatment with NTZ lessened the serum liver enzymes, reduced malondialdehyde (lipid peroxidation product), enhanced antioxidant capacity, attenuated proinflammatorycytokines,andsuppressedapoptosis.Theprotective effect of NTZwasdose-dependent,andthefindingsobservedwiththehigh-dose NTZ were similar to those obtained with the ER-stress inhibitor (4-PBA). Conclusion:NTZexertedahepatoprotectiveeffectinMTX-challengedratsthatis mediated via modulation of ER stress and inhibiting apoptosis.