Abstract: An experiment was conducted on commercial Ven cob broiler chickens to investigate the effect of supplementing herbal methionine (methiorep) that replaced synthetic DL methionine (DLM) in the diets of broilers. One hundred and twenty day-old, commercial broiler chicks (Ven Cobb) were randomly divided into two experimental groups, each of which comprised four replicates. Each replicate consisted of 15 birds. Groups were group I - Diet with synthetic DL-methionine at 2 kg ton-1 of feed and group II - Diet with Methiorep (herbal-methionine) at 1 kg ton-1 of feed & DL-methionine at 1 kg ton-1 of feed. The experiment lasted for 42 days. Diets were iso nitrogenous in control and treatment groups and based on corn soy-bean meal. The experiment was designed to investigate comparative efficacy of herbal methiorep and synthetic DL methionine on growth performance, nutrient utilization, immune response and carcass quality traits of broilers. The replacement of 0.1% DLM by 0.1% Methiorep significantly improved live weight gain (P>0.05) and feed conversion ratio (P>0.05). The nitrogen, calcium and phosphorus retention was significantly higher in group II as compared to group I. Dressing % among groups did not differ significantly suggesting that combination of 0.1% herbal methiorep & 0.1% DLM could efficiently replaced 0.2% synthetic DL methionine. Combination of Methiorep & DLM supplemented group was found to elicit humoral as well as cell mediated immune response at par to the group supplemented DLM alone. Group I has also been observed to exert a superior hypocholesterolemic effect than 0.2% synthetic methionine. Methiorep & DLM supplemented group was found to produce higher serum globulins and serum proteins than DLM alone. Considering growth performance, economics and other attributes it could be recommended to replace 0.1% synthetic methionine by 0.1% herbal Methiorep in the diet of broiler chickens.