Two hundred one-day old (Cobb 500) broiler chicks were used to investigate the influence of low crude protein diets (LCP) fortified with synthetic essential and non-essential amino acids (AAs) as well as L-Carnitine for as a new nutrient requirement on growth performance, some serum biochemical parameters, carcass characteristics and economic efficiency. Chicks were randomly divided into four experimental treatments with five replicates per treatment (50 chicks/ treatment; 10 chicks/replicate). Broiler chicks fed standard CP control diet (group 1), group 1 at which CP reduced by 2 %, group 3 and group 4 at which CP was reduced by 4% and 6%, respectively during starter, grower and finisher stages for 42 days. Group 2 fed LCP (decrease by 2%) were recorded marked improvement in feed conversion ratio (P<0.05) while other dietary groups were noted marked (P<0.05) decreased in feed conversion ratio. Also, results indicated that the lowest levels of serum glucose, triglyceride and serum chloride were found in all experimental groups, while these groups had a significant (P<0.05) increased HDL-cholesterol concentration. Percentage weights of all carcass characteristics had no marked (P>0.05) effect on broilers fed on LCP (P>0.05). The broiler chickens fed on (LCP) decreased by 2% had the best growth performance and net profit values. In conclusions, our data shows that crude protein was reduced up to 6% with synthetic essential and non-essential amino acids fortification without affecting the broiler performance.