Azathioprine (Aza) is an important drug commonly used in the therapy of autoimmune system disorders. It induces hepatotoxicity and hazard effects that restrict its use. The effects of administration of grape seed extract and folic acid on Aza toxicity by gavage (simultaneously) daily for 4 weeks were studied by determining the changes in some hematological parameters and liver histology. The glutathione level (GSH) and lipid peroxidation content as malondialdehyde (MDA) in the liver tissue were measured. The repeated intake of Aza (25 mg/kg body weight) induced anemia characterized by decreased erythrocyte and leukocyte counts and reticulocyte and hematocrit percentages, while the prothrombin time was significantly increased. Moreover, Aza caused a significant decrease in phagocytic activity and lymphocyte percentage. Aza induced hepatic damage as indicated by pronounced changes in the histological structure, a significant increase in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), and MDA content in the liver tissue. Meanwhile, the GSH activity was significantly decreased. Co-treatment with grape seed extract and Aza minimized the previously mentioned hazard effects of Aza and significantly protected the hepatic tissue by ameliorating the antioxidant activity. Folic acid administration, simultaneously, with Aza only improved the anemia. It may be concluded that grape seed extract is a useful herbal remedy, especially for controlling oxidative damages and is considered as a potent protective agent against Aza hepatotoxicity.