This study aimed to assess the impacts of betaine supplementation on growth performance, carcass characteristics, and oxidative status of broilers. A total of 240 one-day-old unsexed (Ross 308 classic FF) broiler chicks were randomly distributed into 4 equal groups (60 birds into 3 replicates/group). The 1st group (control) was fed a diet without any betaine, while betaine was added at levels of 1, 2, and 3 g per kg of feed, respectively at the 2nd, 3ed and 4th groups. At the age of 5 wks, the best values of productive performance represented in body weight, weight gain, feed consumption and feed conversion ratio were achieved in groups fed a diet supplemented with 1 and 2 g betaine/kg of diet. No significant (P˃0.05) differences between all treatments for carcass characteristics, except for the relative weight of both thymus and bursa which were increased by increasing the betaine supplementation level from 1 up to 3 g/kg of feed. A significant (P≤0.01) improvement was achieved in antioxidant status; especially in the levels of both TAC and SOD enzymes while, decreasing the amount of MDA in blood plasma. It could be recommended that, supplementation of betaine in broiler diet at the level of 2g/kg diet affected positively productive performance and antioxidant activity during the growing period.