Introduction: Improvement of the immune response of broiler chickens is an important topic in broilers industry. The use of trace elements and vitamins for such purpose is still interesting issue in the biochemical research arena. Aim:The current study aimed to compare between the effect of selected trace elements and that of ascorbic acid on serum protein patterns of broiler chickens. Materials and Methods:Seventy-five broiler chickens were divided into 5 equal groups. Birds in the group 1 kept on basal diet only and served as a control group. Birds in the groups 2-4 were kept on basal diet mixed with same dose (100mg/kg diet) of ascorbic acid, copper sulphate or zinc sulphate, respectively, whereas birds in the group 5 kept on basal diet mixed with 10mg/kg diet of potassium iodide. Birds were immunized through wing vein injection with 1ml of 5% sheep red blood cells suspension after twoweeks from the start of the experiment. The other wing vein was used for blood samples collection at 2 and 4weeks post immunization. The harvested sera were used for colorimetric determination of serum total protein, albumin and total globulin. In addition, serum globulin fractions (α, ß and γ) were determined by salt fractionation. Results:The current findings indicated that, zinc sulphate or ascorbic acid were potent immunostimulents as evidenced by increased concentrations of serum total proteins, total globulins and γ-globulin fraction of preimmunized chickens fed diet mixed with either zinc sulphate or ascorbic acid compare to control. However, the immunostimulant effect of zinc sulphate was more pronounced. Copper sulphate was immunosuppressive as reflected on decreased total globulins and γ-globulin fraction in the serum of preimmunized chickens compare to control. Potassium iodide did not affect the serum protein patterns of the examined birds. Conclusion:The current study recommended the addition of the examined dose of zinc sulphate or ascorbic acid to the diet of broiler chickens. However, addition of the examined dose of copper sulphate to the diet of broiler chickens is not recommended. Ascorbic acid (AA) is important for many biochemical processes. Keywords 10Dietary supplementation of AA has been selected as a suitable and successful method to ameliorate the detrimental effects of heat stress in broiler chicken. 4 It has been reported that, ascorbic acid is also included in diets to improve feed intake, egg production and egg quality in poultry.11 Ascorbic acid is not typically added to poultry diets 12 because they can synthesize it to meet their physiological needs. However, under a heat stress the metabolic need for ascorbic acid exceeds the synthesizing capacity of the birds. 13 Therefore, ascorbic acid supplementation plays a major role in the improvement of poultry production performance. Because of, biologically active substances in poultry meat can be increased by supplementing broilers feed with vitamins and minerals, 14 the current study aimed to compare the effect of selected trace elements with...