A6-weeks study was designed to evaluate the growth performance, biochemical parameters, immune response and thyroid hormones of broiler chickens in response to feeding diets enriched with different types of natural antioxidants. Two hundred and fifty unsexed Arbor Acres broiler chicks were used in the present study.Day-old chicks were individually weighed and randomly divided into five dietary treatments with five replications of ten chicks each. Growth performance was measured. Serum concentrations of immunoglobulins(IgA, IgG and IgM)mg/dl, total antioxidant capacity(TAC) nmol/ml, malondialdehyde(MDA)U/ml/h and thyroid hormones:thyroxine(T4)ng/ml and triiodothyronine(T3)ng/ml were determined. Activity of superoxide dismutase(SOD)U/ml/h in blood serum was also measured. The results obtained revealed that feeding the natural antioxidants-supplemented diets to Arbor Acres broiler chicks positively affected (P≤0.05) their LBW, BWG and FCR at 6 weeks of age compared with control graup. The FI of the supplemented groups of chicks was significantly lower (P≤0.05) than that of the control group, except the ascorbic acid-enriched group which consumed comparable amount of feed to that of the control birds. Feeding the natural antioxidants-fortified diets to broilers caused significant increases (P≤0.05) in serum levels of immunoglobulins (IgA, IgG and IgM),SOD andT3 but serum Alb level was not affected., and significantly improved (P≤0.01) serum concentration of TAC compared with the control birds. But serum T4 concentration was significantly higher(P≤0.05) in chicks fed Diet3(contained15% GP)than the control and other experimental groups. Based on the obtained results,it can be concluded that feeding natural antioxidants-enriched diets to broiler chicks have beneficial effects on their growth performance,immunity and antioxidant status.