Background: Artichoke extract (AE), containing natural antioxidant compounds, can be considered as a good source of antioxidant potential. OBJECTIVES: The aim of this study was to evaluate antioxidant abilities of AE on broiler meat quality. METHODS: 200 Ross chicken broilers were divided into five equal groups and received 100, 200, 300, and 500 mg/liter of AE in drinking water and pure water in the control group, respectively. Antiradical activity and phenolic content of AE were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and gallic acid measurement before adding extract into drinking water. The broilers received AE extract form 21-35 day of growing phase and the samples from thigh muscles were taken for biochemical analysis in the 42 day of the growing phase. RESULTS: Antiradical activity of AE was 35% and phenolic content was 3.3 g/100g of dry extract. Regarding antioxidant enzymes, such as glutathione peroxidase (GPx) and catalase (CAT), the AE with dosage of 200 mg/l indicated maximum antioxidant ability compared to the other groups (p<0.05). Supplementation of AE200 mg/l also demonstrated the lowest GPx and CAT activities, compared to the control and AE 300 mg/l groups (p<0.05). Regarding performance weight gain, average daily weight gain, percentage of weight gain in 21 to 35 as well as final weight were similar in control and AE-received groups and AE indicated similar effect for all the treatments. CONCLUSIONS: This study showed that administration of 200 mg/l AE in drinking water during growing phase decreased GPx and CAT activities in chicken meat presumably due to down-regulation of gene expression for antioxidant enzymes.