Methotrexate induced liver injury is one of major problem resulted from it is use Previous study found that one of mechanism responsible for liver injury caused by methotrexate is oxidative stress, Alfa lipoic acid is an antioxidant and antiinflammatory dietary supplement. Aim of study is to investigate the protective effect of low and high dose of Alfa lipoic acid on methotrexate induced acute liver injury. Twenty eight male adult albino mice were divided into 4 group and in each group 7 mice, group 1 were administered distilled water and sodium bicarbonate orally by oral gavage for ten days and injected intrperitoneally normal saline on the tenth day only, group 2 were injected MTX intraperitoneally on the tenth day only, group 3 were administered orally 60 mg/kg Alfa lipoic acid orally for ten days and injected methotrexate intraperitoneally on the tenth day ,group 4 were administered orally 120mg/kg Alfa lipoic acid for ten days and injected methotrexate on the tenth day , after two days of the last treatment , the mice were anesthesized and blood was withdrawn for biochemical assessment of liver function , then sacrifing the mice and the liver was dissected out for liver tissue oxidative stress biomarker determination and histopathological study. The results show that serum level of liver enzyme and lipid peroxidation was increase ,reduced glutathione and superoxide dismutase was decrease in methotrexate group, group pretreated with 60mg/kg alfa lipoic acid was showed an improvement of liver enzyme elevation and decrease level of MDA , group pretreated with 120 mg/kg alfa lipoic acid was showed more improvement in liver enzyme elevation and induce more reduction of malondialdehyde and increase level of reduced glutathione. Conclusion: pretreatment by utilizing high dose of alfa lipoic acid lead to produce more significant protection against methotrexate induced liver injury.