Abstract The ban of antibiotic growth promoters in many countries has increased the use of plant bioactives as alternatives to antibiotics; however, there is little information on the impact of sunflower extract on animal performance. Therefore, this study focused on the use of sunflower extract on growth performance and serum antioxidant enzymes of broiler chickens. Unsexed broiler chicks (n = 128; 1 d of age) were completely randomized into group 1 (Con: 0 mL of extract; n = 32), group 2 (2SE: 2mL/L of extract, n = 32), group 3 (4SE: 2mL/L of extract; n = 32) and group 4 (6SE: 2mL/L of extract; n = 32). Each group was replicated 4 times with 8 chicks per replicate. Data was analyzed as one-way ANOVA using SAS 9.4 at 5% alpha. There was no significant (P = 0.0605) difference in final body weight (BW), BW gain (P = 0.0557) and average daily gain of the chickens. The BW gain was 1,727.54g, 1,970.87g, 1,913.86 g and 1,765.53 g for CON, 2SE, 4SE and 6SE respectively. There was significant (P < 0.05) difference in superoxide dismutase and glutathione peroxidase while no significant difference was observed in catalase enzyme activity. In conclusion, sunflower extract could increase the antioxidant status of broiler chickens by scavenging free radicals, it has the potential to increase growth performance, thereby increasing broiler productivity and welfare.