The main objective of this study was showing the effect of myrrah extract at different levels as growth promoters on growth performance, feed utilization, whole-body composition and Aeromonas hydrophila; challenge for all-male Nile tilapia, Oreochromis nilocticus fingerlings. Four experimental diets were formulated to contain 0.0 (control) and 0.5, 1, and 1.5% for myrrah. All diets are isonitrogenous (30% crude protein) and isocaloric (4.4 kcal/gm GE). The study was conducted in triplicate treatments. Each aquarium was stocked with 15 fingerlings of an average weight 12±2 gm. Experimental  diets were provided at a rate of 3 % of live body weight of total biomass, twice/day, 6 days a week, for 90 days. Diet containing 1% Myrrah resulted significantly (p < 0.05) in improvement in growth performance and feed utilization as reflected in gain %, Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Feed Efficiency Ratio (FER), Protein Efficiency Ratio (PER), Apparent Protein Utilization (APU) and Energy Utilization (EU). The survival rate was enhanced due to the inclusion of myrrah in fish diets. With regard to body composition, there was no significant difference in dry matter, protein, lipids, and ash (p > 0.05) contents which could be related to the levels of mirra meal in the experimental diets. Blood plasma profile showed an improvement in Hemoglobin (Hb), Red Blood Cells (RBCs), hematocrit (PCV), total protein, albumin and globulin while showed a decrease in creatinine, urea, Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) and glucose in all treatment groups. Myrrah were found to have antibacterial activity antagonized to A. hydrophila in O. niloticus.