BACKGROUND: Using commercial antioxidants in the diet of chicken may cause cancer, liver swelling and changes in the activity of enzymes, hence their use is limited. Alternative herbal materials with antioxidant and antimicrobial properties can increase palatability, improve gastrointestinal function, improve the immune system and the performance of birds. OBJECTIVES: The purpose of the experiment was to study the effect of pomegranate peel extract (PPE) to a soybean oil diet on broiler performance and other related parameters. METHODS: This research was conducted as completely randomized design arranged in a 2×2×2 factorial experiment using pomegranate peel extract (PPE), antioxidant Nutriad® (AN) and soybean oil (SO). Three hundred and twenty 11 day-old Ross 308 broiler chicks were assigned to eight treatments of four replicates each (ten chicks per replicate). Data were analyzed using the GLM procedure of the SAS software, and the LSM of groups compared at 5% significance level. RESULTS: Soybean oil increased growing and overall feed conversion ratio (FCR) and harmful gastric micro flora. The overall ADG and feed intake were increased by PPE. Inclusion of PPE in the diet had no effect on FCR. Inclusion of PPE in the diet increased nutrient digestibility, beneficial gastric micro flora, lactobacillus, and the antibody titer in 39-day broilers, whereas AN had no effect on any of the performance parameters and decreased the beneficial gastric micro flora. CONCLUSIONS: The overall results showed that PPE in fat and non-fat containing diets might have the potential to increase the daily gain by enhancing feed intake, nutrient digestibility, beneficial gastric micro flora and immune system of broilers with  no deleterious effect on overall FCR.