In the present study the antioxidant activity of Acacia nilotica leaf in growing rabbits was performed. Thirty weaned V-line rabbits aged 35 days (5 weeks) weighed 510g±8.30 (mean±SE) used for the study which lasted for 84 days (12 weeks). Animals were divided equally and randomly into three groups (10 in each one). The first group was fed ad libitum a commercial pelleted diet, while the other groups (second and third) were fed the same diet plus administration with oral daily Acacia nilotica leaf extract at a dose 100 (low dose) and 200 mg /kg body weight (high dose) respectively for 7 weeks. Treatment with aqueous ethanolic leaf extract of Acacia nilotica resulted in significant (p<0.05) increase in blood plasma total protein, albumin and globulin, while blood plasma aminotransferase (AST) and alanineaminotransferase (ALT), alkaline phosphatase (ALP), urea, triglyceride (TG) and glucose levels were significantly decreased as compared to untreated group (control). Results showed that the Acacia nilotica leaves extract has significant antioxidant effect by increasing blood plasma Glutathione peroxidase (GPx) and catalase and decrease blood plasma thiobarbituric acidreactive substances (TBARS) activity as compared to control. The effect of Acacia nilotica leaves extract showed better response as dose dependent. This potential activity of Acacia nilotica leaf might be due to the presence of its phytochemicals or the collective action of many active ingredients. It could be concluded that Acacia nilotica leaf extract treatment significantly improved physiological and antioxidant activity of growing rabbit and this improved was dose dependent.