An 8-week feeding trial was carried out to evaluate the effect of graded levels of synthetic methionine on the growth performance, blood and carcass characteristics of broiler chickens. A total of 120 day-old chicks of Amobyn strain with mean body weight of 36.67g were randomly divided into four groups of 30 chicks each to constitute treatments T1 (0% control), T2 (0.20% methionine), T3 (0.40% methionine) and T4 (0.60% methionine), respectively. Each group was further divided into three replicates of 10 birds each in a Completely Randomized Design (CRD). Feed and water were provided ad libitum and all the birds were managed on a deep litter floor under the same environmental conditions for 56 days. All data were subjected to One- way analysis of variance and significant mean values were separated using Duncan Multiple Range Test. The results obtained for starter broiler chickens showed that total feed intake, weekly feed intake, daily feed intake and feed conversion ratio were significantly (P<0.05) influenced by dietary treatments while the results for finisher chickens showed that only the final body weight was significantly (P< 0.05) influenced. The blood characteristics showed that monocytes, mean corpuscular volume and mean corpuscular haemoglobin concentration were significantly (P<0.05) influenced by dietary treatments. The serum biochemical indices showed no significant (P>0.05) differences between dietary treatments on all parameters. Carcass characteristics showedsignificant (P<0.05) differences between dietary treatment in pre- slaughter weight, lungs weight, intestinal length, intestinal weight as well as weight of spleen and oesophagus. Therefore, this study concludes that syntheticmethionine can be included in the diets of broiler chickens up to 0.60% without detrimental effects on their growth performance, blood and carcass characteristics.Keywords: Synthetic methionine, chicken, growth, blood, carcas