Broilers raised in heat stress conditions produce more free radicals, which cause oxidative stress. An experiment was conducted to study some strategies to ameliorate the effect of chronic heat stress on broiler chicks. A total number of 300 male broiler chicks (ROSS³⁰⁸) 14-day-old were used with three treatments: CONT (control-without any supplementation), SBC (sodium bicarbonate 1g/kg diet) and AA (ascorbic acid 1g/kg diet) supplemented for 21 days starting from 15-day-old chicks.  All treatments were kept under 32±1°C throughout the trial period. Liver samples were collected at 5 weeks of age and grow out performance measurements were calculated over the 21-day study. Results of liver total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and cytochrome c oxidase (CCOX) activities insignificantly decreased in SBC and AA, respectively, and glutathione peroxidase (GSH-PX), insignificantly increased in SBC and AA, respectively compared to CONT. SBC and AA increased significantly (P≤0.05) body weight (BWT), daily weight gain (DWG), and daily feed intake (DFI) at 3 and 4 weeks of age, while significantly increased (P≤0.05) body weight and increased daily feed intake at 5 weeks of age. These results indicate that SBC and AA may enhance the antioxidant capacity as a beneficial effect on broiler performance under chronic heat stress.