this study was conducted in order to assess the effects of dietary Jumbo Cube as source of Monosodium Glutamate (MSG) on production performances of broiler chickens. 320 day-old Ross 308 broiler chicks were randomly divided into five groups of 64 chicks each. Negative and positive control groups were fed on basal diet with no supplement (R0-) and 1 gm of antibiotic (R0+) respectively and the 3 others groups were fed on diets supplemented with the quantities of Jumbo cube containing 1 mg, 2 mg and 4 mg of MSG/Kg of feed. Feed intake (FI), feed conversion ratio (FCR), weight gain (WG), blood parameters and intestinal microbial counts were evaluated. Results revealed that feeding broilers with Jumbo Cube as MSG source significantly (P<0.05) decreased FI at the starter phase with no significant effect at the finisher phase. Diet supplemented with 2 mg of MSG/Kg significantly (P<0.05) increased LBW and WG, and decreased FCR. Dietary MSG significantly (P<0.05) has no significant effect on bacteria counts during starter phase. At the finisher phase, GMS induced a significant increase in lactic bacteria and E. coli counts as compared to the control ration without any supplement. White blood cells (WBC) significantly decreased with inclusion of 1mg and 2 mg of MSG/Kg. Dietary MSG markedly decreased albumin/globulin ratio, LDL-cholesterol and creatinine. It was concluded that Jumbo Cube can be used as source of MSG (2 mg/Kg) to improve growth performance in broiler chickens.