An experiment was conducted on Arbor Acress broiler chicks to evaluate the effects of coconut meat waste (CMW) supplemented with 10 10 CFU/kg CMW of thermophilic bacteria (Bacillus sp. SM-1.4) and 800 U/kg diets of thermostable mannanase on performance and gut histomorphology of broilers. One hundred and fifty of day-old chicks (unsexed) were used in this study. The birds were fed five diets containing coconut meat waste supplemented with bacteria and mannanases (CBM); 0% CBM, 10% CBM, 20% CBM, 30% CBM, and 40% CBM. Feed and water were available at all times. A completely randomized design was applied in this experiment with five diets and five replicate cages. The parameters determined are performance (feed consumption, body weight gain, and feed conversion ratio), gut histomorphology, and microbiota of broilers. Data were analyzed by analysis of variance according to a completely randomized design and Duncan's Multiple Range Test. Data indicated that feed consumption, body weight gain, and gut histomorphology of birds fed the CMW supplemented with thermophilic bacteria and thermostable mannanase were up to 30% higher than those of birds fed the non-supplemented (0% CBM) diet. The birds fed a 20% coconut meat waste diet supplemented with 10 10 CFU/kg diet thermophilic bacteria, and 800 U/kg CMW thermostable mannanase had higher body weight gain than others and significantly (P<0.05) affected on microbiota of broiler. Adding coconut meat waste supplemented with thermophilic bacteria and thermostable mannanase did not affect the feed conversion ratio. In conclusion, up to 20%, CBM level in the diet could improving performance, gut histomorphology, and composition microbiota of broiler.