Background: The aim of this study was to investigate the effects of different dietary levels of Pennyroyal (Mentha Pulegium L.) essential oil (PEO), probiotic (Bioplus 2B) and antibiotic (Flavophospholipol) on performance, carcass characteristics and nutrients digestibility in broiler chickens in a completely randomize design (CRD). Materials and Methods: The treatments included: A corn-wheat-soybean meal basal diet without any additives as control group and adding three levels of Flavophospholipol (0.015, 0.03 and 0.05 % of diet), three levels of BioPlus-B2 (0.1, 0.2 and 0.3 % of diet) and three levels of Mentha pulegium essential oil (0.03, 0.05 and 0.07 % of diet) to the basal diet. 5 replicates of 12 chicks were allocated to each experimental treatment. Results: The results showed that the treatments significantly affected body weight gain (WG) and feed conversion ratio (FCR) in the all experimental periods (P<0.05); but, they had no significant effect on feed intake (P>0.05). PEO at the level of 0.07% significantly decreased WG during 11-25 d (P<0.05) but observed no effect during 11-25 and 11-42 d in compared to control group (P>0.05). Breast and abdominal fat percentage were not significantly affected by treatments (P>0.05). Lowest crude protein (CP) digestibility was observed in 0.015% antibiotic treatment that was significantly lower than 0.1% probiotic treatment (P<0.05). Conclusion: More significantly, dietary supplements represented desirable performance in compared to antibiotics and control group. Hence, the possible usage of these components as antibiotics alternatives in poultry feeds should be outlined in future.

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