Effect of Gum Arabic (GA), as natural antioxidant in the diet, on growth, carcass, digestibility, liver and kidney functions, antioxidant capacity, immunity, thyroid and testosterone hormones of growing rabbits was studied under Egyptian hot condition. Male APRI line rabbits (n=90) were assigned into 3 groups fed basal diet with 0 (T1), 1 (T2) and 2 (T3) kg GA/ton. Growth performance parameters and viability rate were recorded at age intervals from 5 to 11 wk. Digestibility coefficients, carcass traits, serum biochemicals, antioxidant, immunity, and thyroid and testosterone hormones were determined at 11 wk of age. Results revealed that GA addition increased (P<0.05) growth performance, carcass traits (hind parts and dressing), serum total proteins, albumin, globulin, high-density lipoproteins, glucose, total antioxidant capacity, immunoglobulins, triiodothyronine, tetraiodothyronine and testosterone concentrations. Relative weight of carcass foreparts, weight of full digestive tract, cholesterol, triglycerides and low-density lipoproteins, hepato and renal somatic indexes, urea and malondialdehyde decreased (P<0.05) as affected by GA. In conclusion, dietary supplementation with both levels of GA can enhance productive performance, lipid profile, immune response and antioxidant defense system of growing rabbits under Egyptian summer conditions. The best results were obtained with adding 2 kg GA/ton diet.