L-lysine alpha-oxidase (LOX) is an interested enzyme due to its potential applications in biotechnology and tumor therapy. The objective of this study was to determine the antitumor activity of L-Lysine alpha-oxidase enzyme against Ehrlich ascites carcinoma in adult female albino mice. Adult female albino mice (20-25g) were divided into four groups (10 animals each) and treated for two weeks as follows: group (1) normal mice orally administration with saline and served as control, group (2) (LOX enzyme group): mice were injected with LOX enzyme doses of 300 U/kg daily for one week, group (3) animals female mice were interprotenally injected with 2.5×10⁶ EAC/ml of Ehrlich ascites carcinoma for solid tumor induction, group (4) (LOX enzyme-Tumor group): mice bearing EAC treated with LOX enzyme at the same doses of group (2). Results: Administration of LOX enzyme in combination with EAC ameliorated the EAC-induced liver deterioration. This was monitored from the significant reduction in the level of serum TNF-α, AFP, CEA, ALAT, ASAT, GGT, ALP, cholesterol and triglycerides as well as hepatic MDA and nitric oxide coupled with an improvement in the levels of serum albumin as well as hepatic SOD and GSH. Moreover, the histopathological findings showed a potential protection as the enzyme succeeded in prevention of ascites carcinoma. Inoculation of EAC It could be concluded that LOX enzyme administrated to mice reduce tumor size, inhibit systemic inflammation, improving liver function profile, modulating lipid peroxidation and augmenting antioxidant defense system in EAC bearing mice.