The purpose of this study to investigate the protective and therapeutic effect of Ginkgo biloba leaves extract (GbE) against hepatotoxicity induced by thioacetamide (TAA) in male albino rats.                                                                               
         Rats were injected intraperitonially by TAA in a dose of 200 mg/kg b.wt. twice every week for 28 days (TAA treated group). GbEwas orally administered in a dose 100mg/kg b.wt. for 7 days before the first dose of TAA treatment and during exposure period (Gb protected group) and also after the last dose of TAA treatment for 28 days (Gb treated group). The gained results revealed a significant increases in MDA and NO concentrations in blood and liver of TAA group with concomitant decrease in GSH, GSH-px, SOD and CAT activities. DNA fragmentation percentage, TNF-α concentration, hydroxyproline content and tissue transglutaminase activity were also increased. Serum transaminases, ALP and GGT activates as well as bilirubin content were increased. This study showed that Ginkgo biloba extract has a potential activity against thioacetamide. Induced hepatotoxicity and suggested that the chemical constituents of Ginkgo biloba are effective in modulation of oxidative stress induced by thioacetamide.