The present study was designed to investigate the effects of lemon essential oil on gastrointestinal tract, blood parameter and immune responses. A total of one thousnds and twenty hundred one day old chicks were assigned in 5 treatments including Control, Control diet + 0.1 g/Kg Protexin, Control diet + 0.1 g/kg Virginomycin, control diet + 0.1 and 0.2 g/kg Lemon essential oil with 4 replicates and 60 chicks in each replicate. Digestive organs weight such as liver, gizzard, and the parts of intestine (duodenum, jejunum and ileum) and the length of intestine different parts were not affected by any treatment. Serum metabolite, SRBC response and immunoglobulin G and M were not affected by treatments. Finally, using up to 0.2 g/kg lemon essential oil could be suggested for using in broiler chickens diet.