The present study was planned to evaluate the in vivo growth-promoting effects of clove powder and eugenol in broiler chickens. A total of 144 broiler chicks were randomly allocated to six experimental groups, each consisted of four replicates and each replicate consisted of six chicks. The experimental groups were (I) Basal diet, (II) Standard antibiotic avilamycin treated group, (III) clove powder @ 5 g/kg in feed, (IV) clove powder @ 10 g/kg in feed, (V) eugenol @ 150 mg/kg in feed and (VI) eugenol @ 300 mg/kg in feed. The study was conducted for 42 days. Various growth performance parameters like weekly body weight, body weight gain, feed consumption, feed conversion ratio and mortality were observed and at the end of experiment carcass traits were also assessed.Broilers supplemented with diet containing clove powder and eugenol showed significantly higher body weight and body weight gain as compared to control group and which was comparable to the standard antibiotic supplemented group. Feed conversion ratio (FCR) was significantly improved in clove powder and eugenol supplemented group as compared to control group. Dressing and giblet percentage showed no significant alteration in clove powder and eugenol supplemented birds as compared to control birds. Results revealed that the supplementation of broiler diet with clove powder or eugenol at given dosage significantly improved body weight gain and feed conversion ratio in broiler birds.