The present study was conducted to evaluate the Effect of Thyme essential oil on Performance of Broiler Chicken. Two hundred fourty Mareks disease vaccinated straight run day-old commercial broiler chicks were equally and randomly distributed into four treatment groups which were subdivided into three replicates containing 20 chicks in each, reared on deep litter system in pens up to 6 weeks of age. The dietary treatment groups were the Control diet without Thyme essential oil (A), Broiler ration containing Thyme essential oil, 100 mg/kg diet (B), Broiler ration containing Thyme essential oil, 200% mg/kg diet (C). Broiler ration containing Thyme essential oil, 300 mg/kg diet (D). The significant (P<0.05) body weight and gain in weight was observed in broiler ration containing Thyme 100 mg/kg diet. Feed intake and feed efficiency were found to be non significant in all the treatment groups. The better livability percent was observed in all thyme oil supplemented groups. The higher net profit was obtained in group B. In conclusion, the feed supplemented with thyme essential oil at 100mg/kg resulted in significantly higher body weight gain, improved feed conversion ratio, livability and profit in broiler production.